{
 "schema": "quantcalc-federal-tax-provenance/1",
 "tax_year": 2026,
 "description": "Official sources for every federal rule and constant the QuantCalc engine applies (C backend/src and its JS mirror frontend/js/calc), keyed by rule. Each rule: constant, value, engine (file locations), status (verified | disclosed_model | mismatch), sources, notes, unsourced (reason, or null). Each source: url, title, publisher, kind (statute | regulation | guidance | legislation | federal_register | instructions | agency_page | data | secondary), official (true when the publisher is the government body that sets or enacts the figure, or the text of the statute/regulation itself), establishes, claims (expect = the quote exactly as the source prints it; status = match | phrase), checked (date every quote was last found on the fetched source). The weekly job scripts/check_state_tax_sources.py --provenance re-fetches every source and requires every quote. Seeded 2026-09-28 from scripts/federal-recon/federal-sources-draft.json by scripts/federal-recon/build_federal_provenance.py.",
 "rules": {
  "ord_mfj": {
   "constant": "2026 ordinary brackets MFJ",
   "value": "24,800/100,800/211,400/403,550/512,450/768,700",
   "engine": {
    "c": "backend/src/tax_calculator.c:47-53",
    "js": "frontend/js/calc/constants-2026.js:38-46"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.irs.gov/pub/irs-drop/rp-25-32.pdf",
     "title": "Rev. Proc. 2025-32: 2026 inflation-adjusted items (incl. One Big Beautiful Bill amendments)",
     "publisher": "Internal Revenue Service",
     "kind": "guidance",
     "official": true,
     "claims": [
      {
       "expect": "Not over $24,800 10% of the taxable income",
       "status": "match"
      },
      {
       "expect": "Over $24,800 but not over $100,800 $2,480 plus 12% of the excess over $24,800",
       "status": "match"
      },
      {
       "expect": "Over $403,550 but not over $512,450 $82,048 plus 32% of the excess over $403,550",
       "status": "match"
      },
      {
       "expect": "Over $512,450 but not over $768,700 $116,896 plus 35%",
       "status": "match"
      },
      {
       "expect": "Over $768,700 $206,583.50 plus 37% of the excess over $768,700",
       "status": "match"
      },
      {
       "expect": "$35,932 plus 24% of the excess over $211,400",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [],
   "unsourced": null
  },
  "ord_hoh": {
   "constant": "2026 ordinary brackets HOH",
   "value": "17,700/67,450/105,700/201,750/256,200/640,600",
   "engine": {
    "c": "backend/src/tax_calculator.c:97-106",
    "js": "frontend/js/calc/constants-2026.js:56-66"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.irs.gov/pub/irs-drop/rp-25-32.pdf",
     "title": "Rev. Proc. 2025-32: 2026 inflation-adjusted items (incl. One Big Beautiful Bill amendments)",
     "publisher": "Internal Revenue Service",
     "kind": "guidance",
     "official": true,
     "claims": [
      {
       "expect": "Not over $17,700 10% of the taxable income",
       "status": "match"
      },
      {
       "expect": "Over $17,700 but not over $67,450 $1,770 plus 12%",
       "status": "match"
      },
      {
       "expect": "Over $67,450 but not over $105,700 $7,740 plus 22%",
       "status": "match"
      },
      {
       "expect": "Over $105,700 but not over $201,750 $16,155 plus 24%",
       "status": "match"
      },
      {
       "expect": "Over $201,750 but not over $256,200 $39,207 plus 32%",
       "status": "match"
      },
      {
       "expect": "Over $256,200 but not over $640,600 $56,631 plus 35%",
       "status": "match"
      },
      {
       "expect": "Over $640,600 $191,171 plus 37%",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [],
   "unsourced": null
  },
  "ord_single": {
   "constant": "2026 ordinary brackets Single",
   "value": "12,400/50,400/105,700/201,775/256,225/640,600",
   "engine": {
    "c": "backend/src/tax_calculator.c:22-28",
    "js": "frontend/js/calc/constants-2026.js:29-37"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.irs.gov/pub/irs-drop/rp-25-32.pdf",
     "title": "Rev. Proc. 2025-32: 2026 inflation-adjusted items (incl. One Big Beautiful Bill amendments)",
     "publisher": "Internal Revenue Service",
     "kind": "guidance",
     "official": true,
     "claims": [
      {
       "expect": "TABLE 3 - Section 1(j)(2)(C) - Unmarried Individuals (other than Surviving Spouses and Heads of Households) If Taxable Income Is: The Tax Is: Not over $12,400",
       "status": "match"
      },
      {
       "expect": "Over $105,700 but not over $201,775 $17,966 plus 24%",
       "status": "match"
      },
      {
       "expect": "Over $201,775 but not over $256,225 $41,024 plus 32%",
       "status": "match"
      },
      {
       "expect": "Over $256,225 but not over $640,600 Over $640,600 $58,448 plus 35% of the excess over $256,225 $192,979.25 plus 37% of the excess over $640,600",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "PDF column order interleaves the last two Single rows; snippet matches the extracted order."
   ],
   "unsourced": null
  },
  "ord_mfs": {
   "constant": "2026 ordinary brackets MFS",
   "value": "12,400/50,400/105,700/201,775/256,225/384,350",
   "engine": {
    "c": "backend/src/tax_calculator.c:72-78",
    "js": "frontend/js/calc/constants-2026.js:47-55"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.irs.gov/pub/irs-drop/rp-25-32.pdf",
     "title": "Rev. Proc. 2025-32: 2026 inflation-adjusted items (incl. One Big Beautiful Bill amendments)",
     "publisher": "Internal Revenue Service",
     "kind": "guidance",
     "official": true,
     "claims": [
      {
       "expect": "Over $256,225 but not over $384,350 $58,448 plus 35% of the excess over $256,225",
       "status": "match"
      },
      {
       "expect": "Over $384,350 $103,291.75 plus 37% of the excess over $384,350",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [],
   "unsourced": null
  },
  "std_ded": {
   "constant": "2026 standard deduction",
   "value": "32,200 MFJ / 24,150 HOH / 16,100 Single / 16,100 MFS",
   "engine": {
    "c": "backend/src/tax_calculator.c:19,44,69,94",
    "js": "frontend/js/calc/constants-2026.js:70"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.irs.gov/pub/irs-drop/rp-25-32.pdf",
     "title": "Rev. Proc. 2025-32: 2026 inflation-adjusted items (incl. One Big Beautiful Bill amendments)",
     "publisher": "Internal Revenue Service",
     "kind": "guidance",
     "official": true,
     "claims": [
      {
       "expect": "Married Individuals Filing Joint Returns and Surviving Spouses (§ 1(j)(2)(A)) $32,200 Heads of Households (§ 1(j)(2)(B)) $24,150",
       "status": "match"
      },
      {
       "expect": "(§ 1(j)(2)(C)) $16,100 Married Individuals Filing Separate Returns (§ 1(j)(2)(D)) $16,100",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "Rev. Proc. 2025-32 §4.14(1)."
   ],
   "unsourced": null
  },
  "aged_63f": {
   "constant": "§63(f) additional std deduction aged/blind 2026",
   "value": "1,650 married / 2,050 unmarried",
   "engine": {
    "c": "backend/src/tax_calculator.h:90-91",
    "js": "frontend/js/calc/constants-2026.js:75"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.irs.gov/pub/irs-drop/rp-25-32.pdf",
     "title": "Rev. Proc. 2025-32: 2026 inflation-adjusted items (incl. One Big Beautiful Bill amendments)",
     "publisher": "Internal Revenue Service",
     "kind": "guidance",
     "official": true,
     "claims": [
      {
       "expect": "the additional standard deduction amount under § 63(f) for the aged or the blind is $1,650. The additional standard deduction amount is increased to $2,050 if the individual is also unmarried and not a surviving spouse",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "Rev. Proc. 2025-32 §4.14(3) (section 4 holds the 2026 items). Code comments and the standard-deduction pages cited the 2025 section (3); corrected 2026-09-28."
   ],
   "unsourced": null
  },
  "ltcg": {
   "constant": "2026 LTCG 0%/15% max amounts",
   "value": "MFJ 98,900/613,700; MFS 49,450/306,850; HOH 66,200/579,600; other 49,450/545,500",
   "engine": {
    "c": "backend/src/tax_calculator.c:31-33,56-58,81-83,109-111",
    "js": "frontend/js/calc/constants-2026.js:123-144"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.irs.gov/pub/irs-drop/rp-25-32.pdf",
     "title": "Rev. Proc. 2025-32: 2026 inflation-adjusted items (incl. One Big Beautiful Bill amendments)",
     "publisher": "Internal Revenue Service",
     "kind": "guidance",
     "official": true,
     "claims": [
      {
       "expect": "Married Individuals Filing Joint Returns and Surviving Spouse $98,900 $613,700 Married Individuals Filing Separate Returns $49,450 $306,850 Heads of Household $66,200 $579,600 All Other Individuals $49,450 $545,500",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "§4.03."
   ],
   "unsourced": null
  },
  "ctc": {
   "constant": "Child tax credit 2026",
   "value": "2,200 max; 1,700 refundable",
   "engine": {
    "c": null,
    "js": "frontend/js/calc/family-credits-2026.js:35-36"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.irs.gov/pub/irs-drop/rp-25-32.pdf",
     "title": "Rev. Proc. 2025-32: 2026 inflation-adjusted items (incl. One Big Beautiful Bill amendments)",
     "publisher": "Internal Revenue Service",
     "kind": "guidance",
     "official": true,
     "claims": [
      {
       "expect": "the maximum amount of the credit allowed under § 24(a) is $2,200",
       "status": "match"
      },
      {
       "expect": "the amount used in § 24(d)(1)(A) to determine the amount of the credit under § 24 that may be refundable is $1,700",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "§4.05."
   ],
   "unsourced": null
  },
  "ctc_statute": {
   "constant": "CTC statutory: $400k/$200k threshold, $500 ODC, $2,500 floor",
   "value": "400,000/200,000/500/2,500",
   "engine": {
    "c": null,
    "js": "frontend/js/calc/family-credits-2026.js:37-43"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/24",
     "title": "26 U.S. Code § 24",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "the threshold amount shall be $400,000 in the case of a joint return ($200,000 in any other case)",
       "status": "match"
      },
      {
       "expect": "shall be increased by $500 for each",
       "status": "match"
      },
      {
       "expect": "Subsection (d)(1)(B)(i) shall be applied by substituting \"$2,500\" for \"$3,000\"",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [],
   "unsourced": null
  },
  "eitc": {
   "constant": "EITC 2026 table",
   "value": "see family-credits-2026.js:53-56; inv. income 12,200",
   "engine": {
    "c": null,
    "js": "frontend/js/calc/family-credits-2026.js:51-56"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.irs.gov/pub/irs-drop/rp-25-32.pdf",
     "title": "Rev. Proc. 2025-32: 2026 inflation-adjusted items (incl. One Big Beautiful Bill amendments)",
     "publisher": "Internal Revenue Service",
     "kind": "guidance",
     "official": true,
     "claims": [
      {
       "expect": "Earned Income Amount $13,020 $18,290 $18,290 $8,680 Maximum Amount of Credit $4,427 $7,316 $8,231 $664",
       "status": "match"
      },
      {
       "expect": "Threshold Phaseout Amount (Married Filing Jointly) $31,160 $31,160 $31,160 $18,140 Completed Phaseout Amount (Married Filing Jointly) $58,863 $65,899 $70,244 $26,820",
       "status": "match"
      },
      {
       "expect": "Threshold Phaseout Amount (All other filing statuses) $23,890 $23,890 $23,890 $10,860 Completed Phaseout Amount (All other filing statuses) $51,593 $58,629 $62,974 $19,540",
       "status": "match"
      },
      {
       "expect": "aggregate amount of certain investment income exceeds $12,200",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "§4.06."
   ],
   "unsourced": null
  },
  "eitc_pct": {
   "constant": "EITC credit/phaseout percentages §32(b)(1)",
   "value": "34/15.98, 40/21.06, 45/21.06, 7.65/7.65",
   "engine": {
    "c": null,
    "js": "frontend/js/calc/family-credits-2026.js:53-56"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/32",
     "title": "26 U.S. Code § 32",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "1 qualifying child 34 15.98 2 qualifying children 40 21.06 3 or more qualifying children 45 21.06 No qualifying children 7.65 7.65",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [],
   "unsourced": null
  },
  "qbi": {
   "constant": "§199A threshold / phase-in end 2026",
   "value": "MFJ 403,500/553,500; MFS 201,775/276,775; other 201,750/276,750",
   "engine": {
    "c": null,
    "js": "frontend/js/calc/constants-2026.js:190-193"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.irs.gov/pub/irs-drop/rp-25-32.pdf",
     "title": "Rev. Proc. 2025-32: 2026 inflation-adjusted items (incl. One Big Beautiful Bill amendments)",
     "publisher": "Internal Revenue Service",
     "kind": "guidance",
     "official": true,
     "claims": [
      {
       "expect": "Married Individuals Filing Joint Returns $403,500 $553,500 Married Individuals Filing Separate Returns $201,775 $276,775 All Other Returns $201,750 $276,750",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "§4.26."
   ],
   "unsourced": null
  },
  "amt": {
   "constant": "AMT exemption / phase-out 2026 (reference; not modeled)",
   "value": "140,200/90,100/70,100; phase-out 1,000,000/500,000",
   "engine": {
    "c": null,
    "js": null
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.irs.gov/pub/irs-drop/rp-25-32.pdf",
     "title": "Rev. Proc. 2025-32: 2026 inflation-adjusted items (incl. One Big Beautiful Bill amendments)",
     "publisher": "Internal Revenue Service",
     "kind": "guidance",
     "official": true,
     "claims": [
      {
       "expect": "Joint Returns or Surviving Spouses Exemption amount $140,200 Unmarried Individuals (other than Surviving Spouses) $90,100 Married Individuals Filing Separate Returns $70,100",
       "status": "match"
      },
      {
       "expect": "Joint Returns or Surviving Spouses $1,000,000 $1,280,400 Unmarried Individuals (other than Surviving Spouses) $500,000 $680,200",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "Not in engine (capital-gains-tlh-2026.js:34 says AMT not modeled)."
   ],
   "unsourced": null
  },
  "fsa": {
   "constant": "Health FSA 2026 (supplement)",
   "value": "3,400 / carryover 680",
   "engine": {
    "c": null,
    "js": "research/data/constants-2027-supplement.json fsa"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.irs.gov/pub/irs-drop/rp-25-32.pdf",
     "title": "Rev. Proc. 2025-32: 2026 inflation-adjusted items (incl. One Big Beautiful Bill amendments)",
     "publisher": "Internal Revenue Service",
     "kind": "guidance",
     "official": true,
     "claims": [
      {
       "expect": "spending arrangements is $3,400. If the cafeteria plan permits the carryover of unused amounts, the maximum carryover amount is $680",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "Rev. Proc. 2025-32 §4.15. The supplement and FSA pages cited the 2025 section (3); corrected 2026-09-28."
   ],
   "unsourced": null
  },
  "estate_gift": {
   "constant": "Estate basic exclusion / annual gift exclusion 2026",
   "value": "15,000,000 / 19,000",
   "engine": {
    "c": null,
    "js": "research/data/constants-2027-supplement.json estate_gift"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.irs.gov/pub/irs-drop/rp-25-32.pdf",
     "title": "Rev. Proc. 2025-32: 2026 inflation-adjusted items (incl. One Big Beautiful Bill amendments)",
     "publisher": "Internal Revenue Service",
     "kind": "guidance",
     "official": true,
     "claims": [
      {
       "expect": "increasing the basic exclusion amount to $15,000,000 for calendar year 2026",
       "status": "match"
      },
      {
       "expect": "For calendar year 2026, the first $19,000 of gifts to any person",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [],
   "unsourced": null
  },
  "irs_news_2026": {
   "constant": "IRS newsroom 2026 inflation item (std ded headline)",
   "value": "16,100/32,200/24,150",
   "engine": {
    "c": null,
    "js": null
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.irs.gov/newsroom/irs-releases-tax-inflation-adjustments-for-tax-year-2026-including-amendments-from-the-one-big-beautiful-bill",
     "title": "IRS releases tax inflation adjustments for tax year 2026, including amendments from the One Big Beautiful Bill",
     "publisher": "Internal Revenue Service (newsroom)",
     "kind": "agency_page",
     "official": true,
     "claims": [
      {
       "expect": "$32,200",
       "status": "match"
      },
      {
       "expect": "$16,100",
       "status": "match"
      },
      {
       "expect": "$24,150",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "secondary official confirmation"
   ],
   "unsourced": null
  },
  "qcd": {
   "constant": "QCD limit 2026 §408(d)(8)",
   "value": "111,000 annual; 55,000 split-interest",
   "engine": {
    "c": "backend/src/rmd.h:33",
    "js": "frontend/js/calc/constants-2026.js:115-118"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.irs.gov/pub/irs-drop/n-25-67.pdf",
     "title": "Notice 2025-67: 2026 retirement plan limitations",
     "publisher": "Internal Revenue Service",
     "kind": "guidance",
     "official": true,
     "claims": [
      {
       "expect": "under section 408(d)(8)(A) is increased from $108,000 to $111,000",
       "status": "match"
      },
      {
       "expect": "pursuant to a one-time election is increased from $54,000 to $55,000",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "Source is Notice 2025-67 (not Rev. Proc. 2025-32)."
   ],
   "unsourced": null
  },
  "qcd_age": {
   "constant": "QCD age 70½ §408(d)(8)(B)(ii)",
   "value": "70½ (engine 1.1.0: from the year the owner reaches 70 when born January-June, else from the year they reach 71)",
   "engine": {
    "c": "backend/src/rmd.h:32",
    "js": null
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/408",
     "title": "26 U.S. Code § 408",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "has attained age 70½",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "Engine 1.1.0 (age clock): rmd.c qcd_allowed_in_year: with a birth month, 70½ falls in the year the owner reaches 70 only when born January to June; without one, from the year they reach 71, never before 70½."
   ],
   "unsourced": null
  },
  "retire_limits": {
   "constant": "401(k)/IRA/catch-up/SIMPLE/415 limits 2026",
   "value": "24,500/8,000/11,250/7,500/1,100/17,000/18,100/4,000/3,850/5,250/72,000/290,000/360,000/150,000/800",
   "engine": {
    "c": null,
    "js": "frontend/data/contribution-limits-2027/contribution-limits-2027.json rows"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.irs.gov/pub/irs-drop/n-25-67.pdf",
     "title": "Notice 2025-67: 2026 retirement plan limitations",
     "publisher": "Internal Revenue Service",
     "kind": "guidance",
     "official": true,
     "claims": [
      {
       "expect": "is increased from $23,500 to $24,500",
       "status": "match"
      },
      {
       "expect": "aged 50 or over is increased from $7,500 to $8,000",
       "status": "match"
      },
      {
       "expect": "in 2026 remains $11,250",
       "status": "match"
      },
      {
       "expect": "is increased from $7,000 to $7,500",
       "status": "match"
      },
      {
       "expect": "is increased from $1,000 to $1,100",
       "status": "match"
      },
      {
       "expect": "is increased in 2026 from $70,000 to $72,000",
       "status": "match"
      },
      {
       "expect": "is increased from $280,000 to $290,000",
       "status": "match"
      },
      {
       "expect": "is increased from $350,000 to $360,000",
       "status": "match"
      },
      {
       "expect": "is increased from $145,000 to $150,000",
       "status": "match"
      },
      {
       "expect": "is increased from $16,500 to $17,000",
       "status": "match"
      },
      {
       "expect": "is increased from $17,600 to $18,100",
       "status": "match"
      },
      {
       "expect": "is increased from $3,500 to $4,000",
       "status": "match"
      },
      {
       "expect": "remains $3,850",
       "status": "match"
      },
      {
       "expect": "remains $5,250",
       "status": "match"
      },
      {
       "expect": "is increased from $750 to $800",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [],
   "unsourced": null
  },
  "roth_savers": {
   "constant": "Roth IRA phase-out and Saver's credit 2026",
   "value": "242k-252k / 153k-168k; saver's 48,500/80,500, 36,375/60,375, 24,250/40,250",
   "engine": {
    "c": null,
    "js": "research/data/constants-2027-supplement.json"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.irs.gov/pub/irs-drop/n-25-67.pdf",
     "title": "Notice 2025-67: 2026 retirement plan limitations",
     "publisher": "Internal Revenue Service",
     "kind": "guidance",
     "official": true,
     "claims": [
      {
       "expect": "between $242,000 and $252,000 for married couples filing jointly",
       "status": "match"
      },
      {
       "expect": "between $153,000 and $168,000",
       "status": "match"
      },
      {
       "expect": "married taxpayers filing a joint return is increased from $47,500 to $48,500",
       "status": "match"
      },
      {
       "expect": "is increased from $79,000 to $80,500",
       "status": "match"
      },
      {
       "expect": "household is increased from $35,625 to $36,375",
       "status": "match"
      },
      {
       "expect": "is increased from $59,250 to $60,375",
       "status": "match"
      },
      {
       "expect": "all other taxpayers is increased from $23,750 to $24,250",
       "status": "match"
      },
      {
       "expect": "is increased from $39,500 to $40,250",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [],
   "unsourced": null
  },
  "hsa": {
   "constant": "HSA / HDHP 2026",
   "value": "4,400 / 8,750; HDHP min 1,700/3,400; OOP 8,500/17,000",
   "engine": {
    "c": null,
    "js": "frontend/hsa-limits-2026/index.html; contribution-limits-2027.json rows 10-16"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.irs.gov/pub/irs-drop/rp-25-19.pdf",
     "title": "Rev. Proc. 2025-19: 2026 HSA and HDHP amounts",
     "publisher": "Internal Revenue Service",
     "kind": "guidance",
     "official": true,
     "claims": [
      {
       "expect": "deductible health plan is $4,400",
       "status": "match"
      },
      {
       "expect": "under a high deductible health plan is $8,750",
       "status": "match"
      },
      {
       "expect": "not less than $1,700 for self-only coverage or $3,400 for family coverage",
       "status": "match"
      },
      {
       "expect": "do not exceed $8,500 for self-only coverage or $17,000 for family coverage",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "HSA catch-up $1,000 is §223(b)(3)(B) (not fetched)."
   ],
   "unsourced": null
  },
  "aca_pct": {
   "constant": "ACA applicable percentage table 2026",
   "value": "<133: 2.10; 133-150: 3.14-4.19; 150-200: 4.19-6.60; 200-250: 6.60-8.44; 250-300: 8.44-9.96; 300-400: 9.96",
   "engine": {
    "c": "backend/src/aca_bridge_optimizer.c:254-264",
    "js": "frontend/js/calc/constants-2026.js:272-284"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.irs.gov/pub/irs-drop/rp-25-25.pdf",
     "title": "Rev. Proc. 2025-25: 2026 applicable percentage table (§36B) and required contribution percentage",
     "publisher": "Internal Revenue Service",
     "kind": "guidance",
     "official": true,
     "claims": [
      {
       "expect": "Less than 133% At least 133% but less than 150% At least 150% but less than 200% At least 200% but less than 250% At least 250% but less than 300% At least 300% but not more than 400%",
       "status": "match"
      },
      {
       "expect": "Initial percentage Final percentage 2.10% 3.14% 4.19% 6.60% 8.44% 9.96% 2.10% 4.19% 6.60% 8.44% 9.96% 9.96%",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "Rev. Proc. 2025-25 §3.01. 2.10% applies below 133% FPL only; 3.14%-4.19% across 133-150%. The aca_bridge_optimizer.c header comment said '2.10% at <=150%' (code was right); corrected 2026-09-28."
   ],
   "unsourced": null
  },
  "aca_cliff_status": {
   "constant": "400% FPL cliff / enhanced PTC expired after 2025",
   "value": "§36B(c)(1)(E) and (b)(3)(A)(iii) limited to 2021-2025",
   "engine": {
    "c": "backend/src/aca_bridge_optimizer.c:44 (ACA_ENHANCED_SUBSIDIES_2026 0)",
    "js": "frontend/js/calc/constants-2026.js:273"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/36B",
     "title": "26 U.S. Code § 36B",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "Temporary rule for 2021 through 2025 In the case of a taxable year beginning after December 31, 2020, and before January 1, 2026, subparagraph (A) shall be applied without regard to \"but does not exceed 400 percent\"",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "No §36B amendment found in full text of Pub. L. 119-37, 119-75 (Consolidated Appropriations Act 2026), 119-86, 119-98, 119-103, 119-108; govinfo RSS titles through Pub. L. 119-111 show no health-subsidy law. congress.gov blocked (403); uscode.house.gov timed out."
   ],
   "unsourced": null
  },
  "aptc_repay": {
   "constant": "Excess APTC repayment cap removed from 2026 (OBBBA §71305)",
   "value": "§36B(f)(2)(B) struck",
   "engine": {
    "c": null,
    "js": null
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.irs.gov/pub/irs-drop/rp-25-32.pdf",
     "title": "Rev. Proc. 2025-32: 2026 inflation-adjusted items (incl. One Big Beautiful Bill amendments)",
     "publisher": "Internal Revenue Service",
     "kind": "guidance",
     "official": true,
     "claims": [
      {
       "expect": "Section 71305 of the OBBBA removes § 36B(f)(2)(B)",
       "status": "match"
      },
      {
       "expect": "effective for taxable years beginning after December 31, 2025",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "Engine models no APTC reconciliation."
   ],
   "unsourced": null
  },
  "fpl48": {
   "constant": "2025 HHS poverty guidelines (used for 2026 coverage), 48+DC",
   "value": "15,650..54,150; +5,500",
   "engine": {
    "c": "backend/src/aca_bridge_optimizer.c:51-61,214",
    "js": "frontend/js/calc/constants-2026.js:242-243"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.federalregister.gov/documents/2025/01/17/2025-01377/annual-update-of-the-hhs-poverty-guidelines",
     "title": "Annual Update of the HHS Poverty Guidelines (90 FR 5917, 2025-01-17)",
     "publisher": "Department of Health and Human Services (Federal Register)",
     "kind": "federal_register",
     "official": true,
     "claims": [
      {
       "expect": "Persons in family/household Poverty guideline 1 $15,650 2 21,150 3 26,650 4 32,150 5 37,650 6 43,150 7 48,650 8 54,150 For families/households with more than 8 persons, add $5,500 for each additional person",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "90 FR 5917."
   ],
   "unsourced": null
  },
  "fpl_ak_hi": {
   "constant": "2025 HHS poverty guidelines AK / HI",
   "value": "AK 19,550..67,710 +6,880; HI 17,990..62,300 +6,330",
   "engine": {
    "c": "backend/src/aca_bridge_optimizer.c:73-78,221-222",
    "js": "frontend/js/calc/constants-2026.js:248-251"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.federalregister.gov/documents/2025/01/17/2025-01377/annual-update-of-the-hhs-poverty-guidelines",
     "title": "Annual Update of the HHS Poverty Guidelines (90 FR 5917, 2025-01-17)",
     "publisher": "Department of Health and Human Services (Federal Register)",
     "kind": "federal_register",
     "official": true,
     "claims": [
      {
       "expect": "2025 Poverty Guidelines for Alaska Persons in family/household Poverty guideline 1 $19,550 2 26,430 3 33,310 4 40,190 5 47,070 6 53,950 7 60,830 8 67,710 For families/households with more than 8 persons, add $6,880",
       "status": "match"
      },
      {
       "expect": "2025 Poverty Guidelines for Hawaii Persons in family/household Poverty guideline 1 $17,990 2 24,320 3 30,650 4 36,980 5 43,310 6 49,640 7 55,970 8 62,300 For families/households with more than 8 persons, add $6,330",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [],
   "unsourced": null
  },
  "irmaa_b": {
   "constant": "IRMAA 2026 Part B tiers (single/MFJ)",
   "value": "floors 109k/137k/171k/205k/500k (MFJ 218k/274k/342k/410k/750k); +81.20/202.90/324.60/446.30/487.00",
   "engine": {
    "c": "backend/src/irmaa.c:28-36,47-51",
    "js": "frontend/js/calc/constants-2026.js:216-230"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.cms.gov/newsroom/fact-sheets/2026-medicare-parts-b-premiums-deductibles",
     "title": "2026 Medicare Parts A & B Premiums and Deductibles",
     "publisher": "Centers for Medicare & Medicaid Services",
     "kind": "agency_page",
     "official": true,
     "claims": [
      {
       "expect": "Less than or equal to $109,000 Less than or equal to $218,000 $0.00 $202.90",
       "status": "match"
      },
      {
       "expect": "Greater than $109,000 and less than or equal to $137,000 Greater than $218,000 and less than or equal to $274,000 $81.20 $284.10",
       "status": "match"
      },
      {
       "expect": "Greater than $137,000 and less than or equal to $171,000 Greater than $274,000 and less than or equal to $342,000 $202.90 $405.80",
       "status": "match"
      },
      {
       "expect": "Greater than $171,000 and less than or equal to $205,000 Greater than $342,000 and less than or equal to $410,000 $324.60 $527.50",
       "status": "match"
      },
      {
       "expect": "Greater than $205,000 and less than $500,000 Greater than $410,000 and less than $750,000 $446.30 $649.20",
       "status": "match"
      },
      {
       "expect": "Greater than or equal to $500,000 Greater than or equal to $750,000 $487.00 $689.90",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [],
   "unsourced": null
  },
  "irmaa_d": {
   "constant": "IRMAA 2026 Part D surcharges",
   "value": "14.50/37.50/60.40/83.30/91.00",
   "engine": {
    "c": "backend/src/irmaa.c:28-36,47-51",
    "js": "frontend/js/calc/constants-2026.js:216-230"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.cms.gov/newsroom/fact-sheets/2026-medicare-parts-b-premiums-deductibles",
     "title": "2026 Medicare Parts A & B Premiums and Deductibles",
     "publisher": "Centers for Medicare & Medicaid Services",
     "kind": "agency_page",
     "official": true,
     "claims": [
      {
       "expect": "Greater than $218,000 and less than or equal to $274,000 $14.50",
       "status": "match"
      },
      {
       "expect": "Greater than $274,000 and less than or equal to $342,000 $37.50",
       "status": "match"
      },
      {
       "expect": "Greater than $342,000 and less than or equal to $410,000 $60.40",
       "status": "match"
      },
      {
       "expect": "Greater than $410,000 and less than $750,000 $83.30",
       "status": "match"
      },
      {
       "expect": "Greater than or equal to $750,000 $91.00",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [],
   "unsourced": null
  },
  "irmaa_mfs": {
   "constant": "IRMAA 2026 MFS (lived with spouse)",
   "value": "<=109k 0; >109k <391k +446.30/+83.30; >=391k +487.00/+91.00",
   "engine": {
    "c": "backend/src/irmaa.c:70-73",
    "js": "frontend/js/calc/constants-2026.js:231-234"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.cms.gov/newsroom/fact-sheets/2026-medicare-parts-b-premiums-deductibles",
     "title": "2026 Medicare Parts A & B Premiums and Deductibles",
     "publisher": "Centers for Medicare & Medicaid Services",
     "kind": "agency_page",
     "official": true,
     "claims": [
      {
       "expect": "Less than or equal to $109,000 $0.00 $202.90 Greater than $109,000 and less than $391,000 $446.30 $649.20 Greater than or equal to $391,000 $487.00 $689.90",
       "status": "match"
      },
      {
       "expect": "Greater than $109,000 and less than $391,000 $83.30 Greater than or equal to $391,000 $91.00",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [],
   "unsourced": null
  },
  "irmaa_poms": {
   "constant": "IRMAA 2026 via SSA POMS HI 01101.020",
   "value": "same tiers",
   "engine": {
    "c": "backend/src/irmaa.c",
    "js": "frontend/js/calc/constants-2026.js"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://secure.ssa.gov/poms.nsf/lnx/0601101020",
     "title": "POMS HI 01101.020: IRMAA sliding scale tables",
     "publisher": "Social Security Administration",
     "kind": "agency_page",
     "official": true,
     "claims": [
      {
       "expect": "More than $109,000 but less than or equal to $137,000 $284.10 $14.50",
       "status": "match"
      },
      {
       "expect": "More than $109,000 but less than $391,000 $649.20",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "secondary official"
   ],
   "unsourced": null
  },
  "partb_base": {
   "constant": "Part B standard premium 2026",
   "value": "202.90",
   "engine": {
    "c": "backend/src/irmaa.c:12 (comment)",
    "js": "frontend/js/calc/irmaa.js:53"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.cms.gov/newsroom/fact-sheets/2026-medicare-parts-b-premiums-deductibles",
     "title": "2026 Medicare Parts A & B Premiums and Deductibles",
     "publisher": "Centers for Medicare & Medicaid Services",
     "kind": "agency_page",
     "official": true,
     "claims": [
      {
       "expect": "The standard monthly premium for Medicare Part B enrollees will be $202.90 for 2026",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [],
   "unsourced": null
  },
  "parta": {
   "constant": "Part A/B deductibles & coinsurance 2026",
   "value": "283 / 1,736 / 434 / 868 / 217",
   "engine": {
    "c": null,
    "js": "research/data/constants-2027-supplement.json"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.cms.gov/newsroom/fact-sheets/2026-medicare-parts-b-premiums-deductibles",
     "title": "2026 Medicare Parts A & B Premiums and Deductibles",
     "publisher": "Centers for Medicare & Medicaid Services",
     "kind": "agency_page",
     "official": true,
     "claims": [
      {
       "expect": "will be $283 in 2026",
       "status": "match"
      },
      {
       "expect": "will be $1,736 in 2026",
       "status": "match"
      },
      {
       "expect": "coinsurance amount of $434 per day",
       "status": "match"
      },
      {
       "expect": "$868 per day for lifetime reserve days",
       "status": "match"
      },
      {
       "expect": "will be $217.00 in 2026",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [],
   "unsourced": null
  },
  "partd_base": {
   "constant": "Part D base beneficiary premium 2026",
   "value": "38.99",
   "engine": {
    "c": null,
    "js": "frontend/js/calc/irmaa.js:65"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.cms.gov/files/document/july-28-2025-parts-c-d-announcement.pdf",
     "title": "CY 2026 Part D national average monthly bid amount and base beneficiary premium (July 28, 2025)",
     "publisher": "Centers for Medicare & Medicaid Services",
     "kind": "guidance",
     "official": true,
     "claims": [
      {
       "expect": "the Part D base beneficiary premium is $38.99",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [],
   "unsourced": null
  },
  "irmaa_fr": {
   "constant": "IRMAA Federal Register notice (boundary wording)",
   "value": "CMS-8091-N",
   "engine": {
    "c": "backend/src/irmaa.c:92",
    "js": null
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.federalregister.gov/documents/2025/11/19/2025-20251/medicare-program-medicare-part-b-monthly-actuarial-rates-premium-rates-and-annual-deductible",
     "title": "Medicare Program; Medicare Part B Monthly Actuarial Rates, Premium Rates, and Annual Deductible Beginning January 1, 2026 (CMS-8091-N)",
     "publisher": "Centers for Medicare & Medicaid Services (Federal Register)",
     "kind": "federal_register",
     "official": true,
     "claims": [
      {
       "expect": "202.90",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "FR doc 2025-20251, 2025-11-19"
   ],
   "unsourced": null
  },
  "ult": {
   "constant": "Uniform Lifetime Table (ages 72-120)",
   "value": "27.4 ... 2.0",
   "engine": {
    "c": "backend/src/rmd.c:10-60",
    "js": "frontend/js/calc/constants-2026.js:380-430"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.ecfr.gov/current/title-26/section-1.401(a)(9)-9",
     "title": "26 CFR 1.401(a)(9)-9: Life expectancy and distribution period tables",
     "publisher": "eCFR (Office of the Federal Register)",
     "kind": "regulation",
     "official": true,
     "claims": [
      {
       "expect": "Age of employee Applicable denominator 72 27.4 73 26.5 74 25.5 75 24.6 76 23.7",
       "status": "match"
      },
      {
       "expect": "117 2.7 118 2.5 119 2.3 120+ 2.0",
       "status": "match"
      }
     ],
     "checked": "2026-09-28",
     "redirect_ok": true
    }
   ],
   "notes": [
    "All 49 rows machine-compared to the eCFR text: 0 differences."
   ],
   "unsourced": null
  },
  "slt": {
   "constant": "Single Life Table (ages 0-120)",
   "value": "84.6 ... 1.0",
   "engine": {
    "c": null,
    "js": "frontend/js/calc/constants-2026.js:456-578"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.ecfr.gov/current/title-26/section-1.401(a)(9)-9",
     "title": "26 CFR 1.401(a)(9)-9: Life expectancy and distribution period tables",
     "publisher": "eCFR (Office of the Federal Register)",
     "kind": "regulation",
     "official": true,
     "claims": [
      {
       "expect": "Age Life expectancy 0 84.6 1 83.7 2 82.8",
       "status": "match"
      },
      {
       "expect": "55 31.6 56 30.6 57 29.8",
       "status": "match"
      },
      {
       "expect": "117 1.6 118 1.4 119 1.1 120+ 1.0",
       "status": "match"
      }
     ],
     "checked": "2026-09-28",
     "redirect_ok": true
    }
   ],
   "notes": [
    "All 121 rows machine-compared: 0 differences. Joint & Last Survivor table not used by the product."
   ],
   "unsourced": null
  },
  "rmd_age": {
   "constant": "SECURE 2.0 applicable age bands",
   "value": "<=1950: 72; 1951-1958: 73; 1959: [Reserved] (code 73); >=1960: 75",
   "engine": {
    "c": "backend/src/rmd.c:86-91",
    "js": "frontend/js/calc/constants-2026.js:591-595"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.ecfr.gov/current/title-26/section-1.401(a)(9)-2",
     "title": "26 CFR 1.401(a)(9)-2: Distributions commencing during an employee's lifetime",
     "publisher": "eCFR (Office of the Federal Register)",
     "kind": "regulation",
     "official": true,
     "claims": [
      {
       "expect": "born on or after January 1, 1951, but before January 1, 1959, the applicable age is age 73; (v) [Reserved]",
       "status": "match"
      },
      {
       "expect": "born on or after January 1, 1960, the applicable age is",
       "status": "match"
      }
     ],
     "checked": "2026-09-28",
     "redirect_ok": true
    }
   ],
   "notes": [
    "1959 cohort = 73 is a disclosed assumption (reg reserved)."
   ],
   "unsourced": null
  },
  "senior": {
   "constant": "OBBBA senior deduction §151(d)(5)(C)",
   "value": "6,000 per qualified individual; 6% over 75k/150k; tax years 2025-2028",
   "engine": {
    "c": "backend/src/tax_calculator.h:81-86",
    "js": "frontend/js/calc/constants-2026.js:81-87"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/151",
     "title": "26 U.S. Code § 151",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "In the case of a taxable year beginning before January 1, 2029, there shall be allowed a deduction in an amount equal to $6,000 for each qualified individual",
       "status": "match"
      },
      {
       "expect": "reduced (but not below zero) by 6 percent of so much of the taxpayer's modified adjusted gross income as exceeds $75,000 ($150,000 in the case of a joint return)",
       "status": "match"
      },
      {
       "expect": "this subparagraph shall apply only if the taxpayer and the taxpayer's spouse file a joint return",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "Codified at IRC §151(d)(5)(C) (added by OBBBA §70103): (C)(i)-(ii) amount per qualified individual, (C)(iii)(I) the 6% phase-out, (C)(v) joint-return requirement. Code comments cited subparagraphs (A)/(B); corrected 2026-09-28."
   ],
   "unsourced": null
  },
  "senior_eff": {
   "constant": "OBBBA §70103 effective date (2025 start)",
   "value": "taxable years beginning after 2024",
   "engine": {
    "c": "backend/src/tax_calculator.h:85",
    "js": "frontend/js/calc/constants-2026.js:85"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.govinfo.gov/content/pkg/PLAW-119publ21/html/PLAW-119publ21.htm",
     "title": "Public Law 119-21 (One Big Beautiful Bill Act), enrolled text",
     "publisher": "U.S. Government Publishing Office (govinfo)",
     "kind": "legislation",
     "official": true,
     "claims": [
      {
       "expect": "SEC. 70103. TERMINATION OF DEDUCTION FOR PERSONAL EXEMPTIONS OTHER THAN TEMPORARY SENIOR DEDUCTION",
       "status": "match"
      },
      {
       "expect": "The amendments made by this section shall apply to taxable years beginning after December 31, 2024. SEC. 70104",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [],
   "unsourced": null
  },
  "senior_irs": {
   "constant": "IRS: senior deduction per individual ($12,000 couple), 2025-2028",
   "value": "6,000 / 12,000",
   "engine": {
    "c": "backend/src/tax_calculator.c:308-324",
    "js": "frontend/js/calc/federal-tax-2026.js:315-321"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.irs.gov/newsroom/working-families-tax-cuts-tax-deductions-for-working-americans-and-seniors",
     "title": "Working Families Tax Cuts: tax deductions for working Americans and seniors",
     "publisher": "Internal Revenue Service (newsroom)",
     "kind": "agency_page",
     "official": true,
     "claims": [
      {
       "expect": "Effective for 2025 through 2028, individuals who are age 65 and older may claim an additional deduction of $6,000",
       "status": "match"
      },
      {
       "expect": "$12,000 total for a married couple where both spouses qualify",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "URL redirects from the old one-big-beautiful-bill-* slug."
   ],
   "unsourced": null
  },
  "salt": {
   "constant": "SALT cap §164(b)(6)-(7) with the 30% phase-down (Schedule A line 5e)",
   "value": "40,000 (2025) / 40,400 (2026), +1%/yr to 2029, 10,000 from 2030; reduced by 30% of MAGI over 500,000 / 505,000 (+1%/yr), floor 10,000; MFS half threshold, half amount",
   "engine": {
    "c": "backend/src/federal_tax.c federal_salt_cap",
    "js": "frontend/blog/2026-tax-brackets-did-not-revert-fire-planning/index.html (40,400)"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/164",
     "title": "26 U.S. Code § 164",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "in the case of any taxable year beginning in calendar year 2025, $40,000",
       "status": "match"
      },
      {
       "expect": "in the case of any taxable year beginning in calendar year 2026, $40,400",
       "status": "match"
      },
      {
       "expect": "reduced by 30 percent of the excess (if any) of the taxpayer's modified adjusted gross income over the threshold amount",
       "status": "match"
      },
      {
       "expect": "in the case of any taxable year beginning in calendar year 2026, $505,000",
       "status": "match"
      },
      {
       "expect": "shall not result in the applicable limitation amount being less than $10,000",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "Modelled: see rule salt_sched_a (the MFS halving, the 101% steps and the Schedule A worksheet)."
   ],
   "unsourced": null
  },
  "tips": {
   "constant": "No tax on tips §224 (reference; not modeled)",
   "value": "25,000; $100 per $1,000 over 150k/300k",
   "engine": {
    "c": null,
    "js": null
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/224",
     "title": "26 U.S. Code § 224",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "shall not exceed $25,000",
       "status": "match"
      },
      {
       "expect": "by $100 for each $1,000 by which the taxpayer's modified adjusted gross income exceeds $150,000 ($300,000 in the case of a joint return)",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "Not used by the product."
   ],
   "unsourced": null
  },
  "overtime": {
   "constant": "No tax on overtime §225 (reference; not modeled)",
   "value": "12,500 / 25,000 joint; 150k/300k",
   "engine": {
    "c": null,
    "js": null
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/225",
     "title": "26 U.S. Code § 225",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "shall not exceed $12,500 ($25,000 in the case of a joint return)",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "Not used by the product."
   ],
   "unsourced": null
  },
  "carloan": {
   "constant": "Car-loan interest §163(h)(4) (reference; not modeled)",
   "value": "10,000; $200 per $1,000 over 100k/200k",
   "engine": {
    "c": null,
    "js": null
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/163",
     "title": "26 U.S. Code § 163",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "for any taxable year shall not exceed $10,000",
       "status": "match"
      },
      {
       "expect": "by $200 for each $1,000 (or portion thereof) by which the modified adjusted gross income of the taxpayer for the taxable year exceeds $100,000 ($200,000 in the case of a joint return)",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "Not used by the product."
   ],
   "unsourced": null
  },
  "niit": {
   "constant": "NIIT §1411 rate and thresholds",
   "value": "3.8%; 250k MFJ / 125k MFS / 200k other",
   "engine": {
    "c": "backend/src/tax_calculator.c:35-36,60,85,113",
    "js": "frontend/js/calc/constants-2026.js:196-199"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/1411",
     "title": "26 U.S. Code § 1411",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "a tax equal to 3.8 percent of the lesser of",
       "status": "match"
      },
      {
       "expect": "in the case of a taxpayer making a joint return under section 6013 or a surviving spouse (as defined in section 2(a)), $250,000",
       "status": "match"
      },
      {
       "expect": "½ of the dollar amount determined under paragraph (1)",
       "status": "match"
      },
      {
       "expect": "in any other case, $200,000",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [],
   "unsourced": null
  },
  "niit_irs": {
   "constant": "NIIT IRS page",
   "value": "250k/125k/200k",
   "engine": {
    "c": "same",
    "js": "same"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.irs.gov/individuals/net-investment-income-tax",
     "title": "Net Investment Income Tax",
     "publisher": "Internal Revenue Service",
     "kind": "agency_page",
     "official": true,
     "claims": [
      {
       "expect": "Married filing jointly - $250,000, Married filing separately - $125,000, Single or head of household - $200,000",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [],
   "unsourced": null
  },
  "ss86": {
   "constant": "SS taxability base / adjusted base §86(c)",
   "value": "25k/32k/0; 34k/44k/0",
   "engine": {
    "c": "backend/src/tax_calculator.c:224-233",
    "js": "frontend/js/calc/federal-tax-2026.js:266-273"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/86",
     "title": "26 U.S. Code § 86",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "(A) except as otherwise provided in this paragraph, $25,000, (B) $32,000 in the case of a joint return, and (C) zero",
       "status": "match"
      },
      {
       "expect": "(A) except as otherwise provided in this paragraph, $34,000, (B) $44,000 in the case of a joint return",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [],
   "unsourced": null
  },
  "p915": {
   "constant": "Pub 915 MFS lived-apart uses $25,000",
   "value": "25,000",
   "engine": {
    "c": "backend/src/tax_calculator.c:230-233",
    "js": "frontend/js/calc/federal-tax-2026.js:241"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.irs.gov/publications/p915",
     "title": "Publication 915, Social Security and Equivalent Railroad Retirement Benefits",
     "publisher": "Internal Revenue Service",
     "kind": "instructions",
     "official": true,
     "claims": [
      {
       "expect": "$25,000 if you are married filing separately and lived apart from your spouse for all of",
       "status": "match"
      },
      {
       "expect": "$0 if you are married filing separately and lived with your spouse at any time during",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "Pub 915 currently shows the 2025 edition (same statutory amounts)."
   ],
   "unsourced": null
  },
  "72t": {
   "constant": "§72(t) 10% additional tax; 59½ exception",
   "value": "10%, 59½ (engine 1.1.0: the age reached in the year; with a birth month, 10% x the share of the year before 59½)",
   "engine": {
    "c": "backend/src/tax_calculator.c:268-277",
    "js": null
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/72",
     "title": "26 U.S. Code § 72",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "shall be increased by an amount equal to 10 percent of the portion of such amount which is includible in gross income",
       "status": "match"
      },
      {
       "expect": "made on or after the date on which the employee attains age 59½",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "Engine 1.1.0 (age clock): without a birth month the tax applies through the year the owner reaches 59 and not from the year they reach 60; with one, only to the share of the year before 59½ (tax_calculator.c early_withdrawal_penalty_share). The §72(t)(2) exceptions of disability, substantially equal periodic payments and separation from service at 55 (50 for public safety) are modelled (rule 72t_exceptions); others are not."
   ],
   "unsourced": null
  },
  "6654": {
   "constant": "Estimated-tax safe harbours §6654(d)/(e) + Form 2210 regular-method penalty",
   "value": "90% / 100% / 110% over 150k (75k MFS); $1,000 de minimis",
   "engine": {
    "c": "backend/src/federal_tax.c federal_est_compute",
    "js": "frontend/js/calc/estimated-tax-2026.js computeUnderpayment"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/6654",
     "title": "26 U.S. Code § 6654",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "exceeds $150,000, clause (ii) of subparagraph (B) shall be applied by substituting \"110 percent\" for \"100 percent\"",
       "status": "match"
      },
      {
       "expect": "shall be applied by substituting \"$75,000\" for \"$150,000\"",
       "status": "match"
      },
      {
       "expect": "reduced by the credit allowable under section 31, is less than $1,000",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "Modelled: see rule estimated_2210."
   ],
   "unsourced": null
  },
  "int_rates": {
   "constant": "IRS underpayment rate by quarter",
   "value": "2025 Q2-Q4 7%; 2026 Q1 7%, Q2 6%, Q3 7%, Q4 7%",
   "engine": {
    "c": null,
    "js": "frontend/js/calc/estimated-tax-2026.js:46-55 (+ inline copy underpayment-penalty-calculator/index.html:465-473)"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.irs.gov/payments/quarterly-interest-rates",
     "title": "Quarterly interest rates",
     "publisher": "Internal Revenue Service",
     "kind": "agency_page",
     "official": true,
     "claims": [
      {
       "expect": "Underpayment (corporate and non-corporate) 7% 7% 6% 7%",
       "status": "match"
      },
      {
       "expect": "4th quarter rates - Internal Revenue Bulletin: 2026-36",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "Rev. Rul. numbers 2025-7/-11/-18/-22, 2026-5/-10/-15 each confirmed in IRB 2025-13/23/37/48, 2026-08/22/36."
   ],
   "unsourced": null
  },
  "cap_loss": {
   "constant": "§1211(b) capital loss limit",
   "value": "3,000 (1,500 MFS)",
   "engine": {
    "c": null,
    "js": "frontend/js/calc/capital-gains-tlh-2026.js:106"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/1211",
     "title": "26 U.S. Code § 1211",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "the lower of- (1) $3,000 ($1,500 in the case of a married individual filing a separate return)",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [],
   "unsourced": null
  },
  "ss_wage_base": {
   "constant": "OASDI wage base 2026",
   "value": "184,500",
   "engine": {
    "c": null,
    "js": "frontend/js/calc/constants-2026.js:168"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.ssa.gov/oact/cola/cbb.html",
     "title": "Contribution and benefit base",
     "publisher": "Social Security Administration, Office of the Chief Actuary",
     "kind": "agency_page",
     "official": true,
     "claims": [
      {
       "expect": "For earnings in 2026, this base is $184,500",
       "status": "match"
      },
      {
       "expect": "The OASDI tax rate for self-employment income in 2026 is 12.4 percent",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [],
   "unsourced": null
  },
  "ss_wage_base_fr": {
   "constant": "OASDI wage base + earnings test (FR 2025-19763)",
   "value": "184,500",
   "engine": {
    "c": null,
    "js": "frontend/js/calc/constants-2026.js:153-166"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.federalregister.gov/documents/2025/11/03/2025-19763/cost-of-living-increase-and-other-determinations-for-2026",
     "title": "Cost-of-Living Increase and Other Determinations for 2026 (FR Doc. 2025-19763)",
     "publisher": "Social Security Administration (Federal Register)",
     "kind": "federal_register",
     "official": true,
     "claims": [
      {
       "expect": "The OASDI contribution and benefit base is $184,500 for remuneration paid in 2026",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [],
   "unsourced": null
  },
  "earn_test": {
   "constant": "Retirement earnings test 2026",
   "value": "24,480 / 65,160",
   "engine": {
    "c": null,
    "js": "frontend/js/calc/constants-2026.js:177-180"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.ssa.gov/oact/cola/rtea.html",
     "title": "Exempt amounts under the earnings test",
     "publisher": "Social Security Administration, Office of the Chief Actuary",
     "kind": "agency_page",
     "official": true,
     "claims": [
      {
       "expect": "the annual exempt amount in 2026 is $24,480",
       "status": "match"
      },
      {
       "expect": "For people attaining NRA in 2026, the annual exempt amount is $65,160",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [],
   "unsourced": null
  },
  "fica_rates": {
   "constant": "FICA rates / Additional Medicare",
   "value": "6.2 / 1.45 / 0.9% over 250k MFJ, 125k MFS, 200k other",
   "engine": {
    "c": null,
    "js": "frontend/js/calc/constants-2026.js:167-176"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/3101",
     "title": "26 U.S. Code § 3101",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "a tax equal to 6.2 percent of the wages",
       "status": "match"
      },
      {
       "expect": "a tax equal to 1.45 percent of the wages",
       "status": "match"
      },
      {
       "expect": "a tax equal to 0.9 percent of wages",
       "status": "match"
      },
      {
       "expect": "in the case of a joint return, $250,000",
       "status": "match"
      },
      {
       "expect": "in any other case, $200,000",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "SE factor 0.9235 derived from §1402(a)(12) (1 - half of 15.3%)."
   ],
   "unsourced": null
  },
  "mileage": {
   "constant": "IRS standard mileage 2026",
   "value": "H1 72.5/20.5/14; H2 76/23.5/14",
   "engine": {
    "c": null,
    "js": "frontend/js/calc/mileage.js:17-18"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.irs.gov/tax-professionals/standard-mileage-rates",
     "title": "Standard mileage rates",
     "publisher": "Internal Revenue Service",
     "kind": "agency_page",
     "official": true,
     "claims": [
      {
       "expect": "2026 (July 1 - Dec. 31) 76 14 23.5",
       "status": "match"
      },
      {
       "expect": "2026 (Jan. 1 - June 30) 72.5 14 20.5",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "Announcement 2026-11 citation confirmed in IRB 2026-29."
   ],
   "unsourced": null
  },
  "hsa_catchup": {
   "constant": "HSA additional (catch-up) contribution, age 55+",
   "value": "1,000 (fixed by statute since 2009; not indexed)",
   "engine": {
    "c": null,
    "js": "frontend/hsa-limits-2026/index.html (page copy, $1,000 at 55+)"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/223",
     "title": "26 U.S. Code § 223",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "establishes": "§223(b)(3)(B): the HSA catch-up is $1,000 for 2009 and later years.",
     "claims": [
      {
       "expect": "the additional contribution amount is the amount determined in accordance with the following table",
       "status": "match"
      },
      {
       "expect": "2009 and thereafter $1,000",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [],
   "unsourced": null
  },
  "partd_2026_params": {
   "constant": "Part D 2026 standard deductible and annual out-of-pocket threshold",
   "value": "615 / 2,100",
   "engine": {
    "c": null,
    "js": "research/data/medicare-ss-figures.json part_d"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.cms.gov/files/document/2027-announcement.pdf",
     "title": "Announcement of Calendar Year 2027 Medicare Advantage Capitation Rates and Part C and Part D Payment Policies",
     "publisher": "Centers for Medicare & Medicaid Services",
     "kind": "guidance",
     "official": true,
     "establishes": "The CY 2027 Rate Announcement states the CY 2026 Part D deductible ($615) and OOP threshold ($2,100) it indexes from.",
     "claims": [
      {
       "expect": "multiplying the 2026 amount of $615 by the 2027 API",
       "status": "match"
      },
      {
       "expect": "multiplying the CY 2026 amount of $2,100 by the 2027 API",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [],
   "unsourced": null
  },
  "aca_age_curve_default": {
   "constant": "ACA federal default age-rating curve, adults 21-64 (premium ratio vs age 21)",
   "value": "21-24: 1.000; 25: 1.004; 26: 1.024 ... 63: 2.952; 64+: 3.000",
   "engine": {
    "c": "backend/src/aca_bridge_optimizer.c AGE_FACTOR_RAW",
    "js": "frontend/js/calc/constants-2026.js AGE_FACTORS"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.cms.gov/CCIIO/Programs-and-Initiatives/Health-Insurance-Market-Reforms/Downloads/StateSpecAgeCrv053117.pdf",
     "title": "State Specific Age Curve Variations (effective plan years beginning on or after January 1, 2018; 5-31-2017)",
     "publisher": "Centers for Medicare & Medicaid Services (CCIIO)",
     "kind": "guidance",
     "official": true,
     "establishes": "The CMS default adult curve used by every state without its own (45 CFR 147.102(e)); ages 21-63 then 64+.",
     "claims": [
      {
       "expect": "1.000 1.000 1.000 1.000 1.004 1.024 1.048 1.087 1.119 1.135 1.159 1.183 1.198 1.214 1.222 1.230 1.238 1.246 1.262 1.278 1.302 1.325 1.357 1.397 1.444 1.500 1.563 1.635 1.706 1.786 1.865 1.952 2.040 2.135 2.230 2.333 2.437 2.548 2.603 2.714 2.810 2.873 2.952",
       "status": "match"
      },
      {
       "expect": "64 and Older 3.000",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "Fixed 2026-09-28 (fed/followups1): the engine carried 1.000 at age 25 until then; C AGE_FACTOR_RAW and JS AGE_FACTORS now equal every Default-column entry, ages 21-64."
   ],
   "unsourced": null
  },
  "aca_age_curve_states": {
   "constant": "State-established adult age curves (DC, MA, UT); AL, MN, MS, OR use the default at adult ages",
   "value": "see STATE_AGE_CURVES",
   "engine": {
    "c": "backend/src/aca_bridge_optimizer.c STATE_AGE_CURVES",
    "js": "frontend/js/calc/constants-2026.js STATE_AGE_CURVES"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.cms.gov/CCIIO/Programs-and-Initiatives/Health-Insurance-Market-Reforms/Downloads/StateSpecAgeCrv053117.pdf",
     "title": "State Specific Age Curve Variations (effective plan years beginning on or after January 1, 2018; 5-31-2017)",
     "publisher": "Centers for Medicare & Medicaid Services (CCIIO)",
     "kind": "guidance",
     "official": true,
     "establishes": "DC, Massachusetts and Utah adult curves, ages 21-63 (64+ repeats the last value).",
     "claims": [
      {
       "expect": "0.727 0.727 0.727 0.727 0.727 0.727 0.727 0.744 0.760 0.779 0.799 0.817 0.836 0.856 0.876 0.896 0.916 0.927 0.938 0.975 1.013 1.053 1.094 1.137 1.181 1.227 1.275 1.325 1.377 1.431 1.487 1.545 1.605 1.668 1.733 1.801 1.871 1.944 2.020 2.099 2.181 2.181 2.181",
       "status": "match"
      },
      {
       "expect": "1.183 1.183 1.183 1.183 1.183 1.183 1.220 1.250 1.275 1.287 1.305 1.323 1.334 1.346 1.352 1.358 1.363 1.369 1.381 1.393 1.410 1.427 1.450 1.478 1.511 1.550 1.593 1.641 1.688 1.741 1.792 1.847 1.902 1.961 2.019 2.080 2.142 2.206 2.280 2.365 2.365 2.365 2.365",
       "status": "match"
      },
      {
       "expect": "1.000 1.050 1.113 1.191 1.298 1.363 1.390 1.390 1.390 1.390 1.390 1.390 1.390 1.390 1.390 1.390 1.404 1.425 1.450 1.479 1.516 1.562 1.616 1.681 1.748 1.818 1.891 1.966 2.045 2.127 2.212 2.300 2.392 2.488 2.588 2.691 2.799 2.911 3.000 3.000 3.000 3.000 3.000",
       "status": "match"
      },
      {
       "expect": "64 and Older 3.000 3.000 2.181 2.365 3.000 3.000 2.280 3.000 3.000",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "NY and VT community rating (no age rating) is state law; see top-level unsourced.",
    "Columns in the PDF: Default, Alabama (Individual), District of Columbia, Massachusetts, Minnesota, Mississippi, New Jersey (Small Group), Oregon, Utah. Checked 2026-09-28 column by column against the engine: AL, MN, MS and OR print the Default column at ages 21-64 (so the default curve prices them, 1.004 at 25 included) and differ only below 21, which the credit excludes; NJ's column applies to the small-group market only. The 64-and-older row pins the last value of every column."
   ],
   "unsourced": null
  },
  "silver_benchmark": {
   "constant": "2026 average benchmark (second-lowest-cost silver) premium, age 40, by state; national fallback",
   "value": "51 state/DC values (aca_bridge_optimizer.c SILVER_2026); national fallback 625",
   "engine": {
    "c": "backend/src/aca_bridge_optimizer.c SILVER_2026 + silver_benchmark() fallback",
    "js": "frontend/js/calc/constants-2026.js SILVER_BENCHMARK_AGE40_2026 / NATIONAL_AVG_SILVER_AGE40_2026"
   },
   "status": "disclosed_model",
   "sources": [
    {
     "url": "https://www.kff.org/affordable-care-act/state-indicator/marketplace-average-benchmark-premiums/",
     "title": "Marketplace Average Benchmark Premiums (State Health Facts)",
     "publisher": "KFF (non-government)",
     "kind": "secondary",
     "official": false,
     "establishes": "Every engine value (51 states + DC) and the US figure used as the fallback, as KFF prints its 2026 column. Non-government: KFF computes these from HealthCare.gov plan data and state-based-marketplace data, weighted by county plan selections.",
     "claims": [
      {
       "expect": "2026 Location Average Benchmark Premium United States 625 Alabama 645 Alaska 1032 Arizona 532 Arkansas 774 California 570 Colorado 557 Connecticut 870 Delaware 691 District of Columbia 610 Florida 683 Georgia 615 Hawaii 541 Idaho 490 Illinois 646 Indiana 474 Iowa 501 Kansas 670 Kentucky 590 Louisiana 646 Maine 709 Maryland 414 Massachusetts 494 Michigan 523 Minnesota 448 Mississippi 662 Missouri 605 Montana 692 Nebraska 710 Nevada 497 New Hampshire 401 New Jersey 545 New Mexico 623 New York 817 North Carolina 638 North Dakota 570 Ohio 513 Oklahoma 604 Oregon 543 Pennsylvania 572 Rhode Island 506 South Carolina 564 South Dakota 655 Tennessee 711 Texas 661 Utah 640 Vermont 1299 Virginia 455 Washington 612 West Virginia 1073 Wisconsin 611 Wyoming 1090",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    },
    {
     "url": "https://www.cms.gov/files/document/2025-qhp-premiums-choice-report.pdf",
     "title": "Plan Year 2025 Qualified Health Plan Choice and Premiums in HealthCare.gov Marketplaces",
     "publisher": "Centers for Medicare & Medicaid Services",
     "kind": "data",
     "official": true,
     "establishes": "CMS's own average benchmark (SLCSP) premium series for HealthCare.gov states. Its state appendix (2025-qhp-premiums-choice-appendix.xlsx, sheet 'Avg. SLCSP Prem. 40yo-State') matches KFF's 2025 benchmark column within $0.50 for all 31 HealthCare.gov states (cross-check 2026-09-28, scripts/federal-recon/silver_benchmark_crosscheck.py). CMS has not published the plan-year 2026 edition, and it never covers state-based marketplaces.",
     "claims": [
      {
       "expect": "Average Benchmark Plan Premium Before APTC 21 Year Old $359 $348 $362 $376 $388",
       "status": "phrase"
      },
      {
       "expect": "40 Year Old $460 $447 $464 $482 $497",
       "status": "phrase"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "DISCLOSED MODEL, not an official figure: no government source publishes a 2026 average benchmark premium for every state. CMS's QHP Choice and Premiums report is the official series but stops at plan year 2025 and covers HealthCare.gov states only; the 2026 OEP public use files (state, county) carry average premiums paid, not benchmarks.",
    "KFF's methodology reproduces CMS's official figures: 31/31 HealthCare.gov states within $0.50 for plan year 2025.",
    "The engine uses a state average, not the enrollee's rating-area SLCSP, so an individual's actual credit can differ; the pages say so.",
    "Recon cited https://www.kff.org/affordable-care-act/state-indicator/average-marketplace-premiums-by-metal-tier/ (same figures, by-metal-tier layout)."
   ],
   "unsourced": null
  },
  "tax_exempt_103": {
   "constant": "Tax-exempt interest (§103) enters Social Security provisional income (§86(b)(2)(B)) but not taxable income",
   "value": "excluded from gross income; added to modified AGI for §86",
   "engine": {
    "c": "backend/src/federal_tax.c (federal_tax_compute: Pub 915 provisional income)",
    "js": null
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/103",
     "title": "26 U.S. Code § 103",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "gross income does not include interest on any State or local bond",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    },
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/86",
     "title": "26 U.S. Code § 86",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "the amount of interest received or accrued by the taxpayer during the taxable year which is exempt from tax",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "Added 2026-09-28 (A1/DOC1): a source for a Form 1040 composition step of the federal engine; every quote checked with scripts/check_state_tax_sources.py --url/--expect."
   ],
   "unsourced": null
  },
  "ira_408d": {
   "constant": "IRA distributions are included in gross income (§408(d)(1))",
   "value": "included in gross income",
   "engine": {
    "c": "backend/src/federal_tax.c (ira_distribution: ordinary income, Form 1040 line 4b)",
    "js": null
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/408",
     "title": "26 U.S. Code § 408",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "any amount paid or distributed out of an individual retirement plan shall be included in gross income by the payee or distributee",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "Added 2026-09-28 (A1/DOC1): a source for a Form 1040 composition step of the federal engine; every quote checked with scripts/check_state_tax_sources.py --url/--expect."
   ],
   "unsourced": null
  },
  "annuity_72": {
   "constant": "Pension and annuity payments are included in gross income (§72(a))",
   "value": "included in gross income",
   "engine": {
    "c": "backend/src/federal_tax.c (pension: part of other_ordinary, Form 1040 line 5b)",
    "js": null
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/72",
     "title": "26 U.S. Code § 72",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "gross income includes any amount received as an annuity",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "Added 2026-09-28 (A1/DOC1): a source for a Form 1040 composition step of the federal engine; every quote checked with scripts/check_state_tax_sources.py --url/--expect."
   ],
   "unsourced": null
  },
  "cg_1222": {
   "constant": "Net short-term, net long-term and net capital gain (§1222)",
   "value": "definitions",
   "engine": {
    "c": "backend/src/federal_tax.c (Schedule D netting)",
    "js": null
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/1222",
     "title": "26 U.S. Code § 1222",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "the excess of short-term capital gains for the taxable year over the short-term capital losses for such year",
       "status": "match"
      },
      {
       "expect": "the excess of long-term capital gains for the taxable year over the long-term capital losses for such year",
       "status": "match"
      },
      {
       "expect": "the excess of the gains from sales or exchanges of capital assets over the losses from such sales or exchanges",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "Added 2026-09-28 (A1/DOC1): a source for a Form 1040 composition step of the federal engine; every quote checked with scripts/check_state_tax_sources.py --url/--expect."
   ],
   "unsourced": null
  },
  "gross_income_61": {
   "constant": "Gross income (§61)",
   "value": "all income from whatever source derived",
   "engine": {
    "c": "backend/src/federal_tax.c (total income, Form 1040 line 9)",
    "js": null
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/61",
     "title": "26 U.S. Code § 61",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "gross income means all income from whatever source derived",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "Added 2026-09-28 (A1/DOC1): a source for a Form 1040 composition step of the federal engine; every quote checked with scripts/check_state_tax_sources.py --url/--expect."
   ],
   "unsourced": null
  },
  "agi_62": {
   "constant": "Adjusted gross income (§62)",
   "value": "gross income minus the §62 deductions (none modelled)",
   "engine": {
    "c": "backend/src/federal_tax.c (AGI, Form 1040 line 11a)",
    "js": null
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/62",
     "title": "26 U.S. Code § 62",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "in the case of an individual, gross income minus the following deductions",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "Added 2026-09-28 (A1/DOC1): a source for a Form 1040 composition step of the federal engine; every quote checked with scripts/check_state_tax_sources.py --url/--expect."
   ],
   "unsourced": null
  },
  "taxable_income_63": {
   "constant": "Taxable income (§63(a), (b))",
   "value": "AGI minus the standard deduction and the deductions allowed",
   "engine": {
    "c": "backend/src/federal_tax.c (Form 1040 lines 14-15)",
    "js": null
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/63",
     "title": "26 U.S. Code § 63",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "gross income minus the deductions allowed by this chapter",
       "status": "match"
      },
      {
       "expect": "adjusted gross income, minus",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "Added 2026-09-28 (A1/DOC1): a source for a Form 1040 composition step of the federal engine; every quote checked with scripts/check_state_tax_sources.py --url/--expect."
   ],
   "unsourced": null
  },
  "form_1040_lines": {
   "constant": "Form 1040 and schedules: the line each engine value is reported on (TY2025 forms; the TY2026 forms are not yet published)",
   "value": "line labels",
   "engine": {
    "c": "backend/src/federal_tax.c (FedTrace line ids)",
    "js": null
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.irs.gov/pub/irs-pdf/f1040.pdf",
     "title": "Form 1040 (2025): U.S. Individual Income Tax Return",
     "publisher": "Internal Revenue Service",
     "kind": "instructions",
     "official": true,
     "claims": [
      {
       "expect": "Tax-exempt interest",
       "status": "match"
      },
      {
       "expect": "IRA distributions",
       "status": "match"
      },
      {
       "expect": "Pensions and annuities",
       "status": "match"
      },
      {
       "expect": "Social security benefits",
       "status": "match"
      },
      {
       "expect": "Capital gain or (loss). Attach Schedule D if required",
       "status": "match"
      },
      {
       "expect": "Additional income from Schedule 1, line 10",
       "status": "match"
      },
      {
       "expect": "This is your total income",
       "status": "match"
      },
      {
       "expect": "This is your adjusted gross income",
       "status": "match"
      },
      {
       "expect": "Standard deduction or itemized deductions (from Schedule A)",
       "status": "match"
      },
      {
       "expect": "Additional deductions from Schedule 1-A, line 38",
       "status": "match"
      },
      {
       "expect": "Add lines 12e, 13a, and 13b",
       "status": "match"
      },
      {
       "expect": "This is your taxable income",
       "status": "match"
      },
      {
       "expect": "Tax (see instructions)",
       "status": "match"
      },
      {
       "expect": "Other taxes, including self-employment tax, from Schedule 2, line 21",
       "status": "match"
      },
      {
       "expect": "This is your total tax",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    },
    {
     "url": "https://www.irs.gov/pub/irs-pdf/f1040s1a.pdf",
     "title": "Schedule 1-A (Form 1040) (2025): Additional Deductions",
     "publisher": "Internal Revenue Service",
     "kind": "instructions",
     "official": true,
     "claims": [
      {
       "expect": "Enhanced deduction for seniors. Add lines 36a and 36b",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    },
    {
     "url": "https://www.irs.gov/pub/irs-pdf/f1040s2.pdf",
     "title": "Schedule 2 (Form 1040) (2025): Additional Taxes",
     "publisher": "Internal Revenue Service",
     "kind": "instructions",
     "official": true,
     "claims": [
      {
       "expect": "Additional tax on IRAs or other tax-favored accounts",
       "status": "match"
      },
      {
       "expect": "Net investment income tax. Attach Form 8960",
       "status": "match"
      },
      {
       "expect": "These are your total other taxes",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    },
    {
     "url": "https://www.irs.gov/pub/irs-pdf/f1040sd.pdf",
     "title": "Schedule D (Form 1040) (2025): Capital Gains and Losses",
     "publisher": "Internal Revenue Service",
     "kind": "instructions",
     "official": true,
     "claims": [
      {
       "expect": "Net short-term capital gain or (loss)",
       "status": "match"
      },
      {
       "expect": "Net long-term capital gain or (loss)",
       "status": "match"
      },
      {
       "expect": "Combine lines 7 and 15 and enter the result",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "Added 2026-09-28 (A1/DOC1): a source for a Form 1040 composition step of the federal engine; every quote checked with scripts/check_state_tax_sources.py --url/--expect."
   ],
   "unsourced": null
  },
  "sched_a_medical": {
   "constant": "Medical and dental expenses §213(a) over 7.5% of AGI (Schedule A line 4)",
   "value": "7.5% of AGI",
   "engine": {
    "c": "backend/src/federal_tax.c ext_deduction",
    "js": null
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/213",
     "title": "26 U.S. Code § 213",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "to the extent that such expenses exceed 7.5 percent of adjusted gross income",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [],
   "unsourced": null
  },
  "charity_limits": {
   "constant": "Charitable deduction limits §170(b)(1)(C)/(G)/(H) and the OBBBA 0.5% floor §170(b)(1)(I)",
   "value": "capital-gain property 30%, cash 60% less (A) contributions, contribution base = AGI; 2026+: allowed only above 0.5% of the contribution base, applied to (C) before (G)",
   "engine": {
    "c": "backend/src/federal_tax.c ext_deduction",
    "js": null
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/170",
     "title": "26 U.S. Code § 170",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "shall not exceed 30 percent of the taxpayer's contribution base for such year",
       "status": "match"
      },
      {
       "expect": "60 percent of the taxpayer's contribution base for the taxable year, over (II) the aggregate amount of contributions taken into account under subparagraph (A) for such taxable year",
       "status": "match"
      },
      {
       "expect": "the term \"contribution base\" means adjusted gross income (computed without regard to any net operating loss carryback to the taxable year under section 172)",
       "status": "match"
      },
      {
       "expect": "shall be allowed only to the extent that the aggregate of such contributions exceeds 0.5 percent of the taxpayer's contribution base for the taxable year",
       "status": "match"
      },
      {
       "expect": "(ii) second, by taking into account charitable contributions to which subparagraph (C) applies to the extent thereof",
       "status": "match"
      },
      {
       "expect": "(vi) sixth, by taking into account charitable contributions to which subparagraph (G) applies to the extent thereof",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    },
    {
     "url": "https://www.govinfo.gov/content/pkg/PLAW-119publ21/html/PLAW-119publ21.htm",
     "title": "Public Law 119-21 (One Big Beautiful Bill Act), enrolled text",
     "publisher": "U.S. Government Publishing Office (govinfo)",
     "kind": "legislation",
     "official": true,
     "claims": [
      {
       "expect": "SEC. 70425. 0.5 PERCENT FLOOR ON DEDUCTION OF CONTRIBUTIONS MADE BY INDIVIDUALS",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "Carryovers (5 years) of contributions over the percentage limits, and of amounts disallowed by the floor, are not modelled: the excess is not deducted in the year (disclosed in federal_tax.c). Only cash and capital-gain property to public charities are modelled (no private-foundation 20%/30% classes)."
   ],
   "unsourced": null
  },
  "charity_170p": {
   "constant": "Non-itemizer charitable deduction §170(p) (OBBBA §70424)",
   "value": "1,000 (2,000 joint), cash to public charities, not DAFs / §509(a)(3); taxable years after 2025; no 0.5% floor",
   "engine": {
    "c": "backend/src/federal_tax.c ext_deduction",
    "js": null
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/170",
     "title": "26 U.S. Code § 170",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "if the individual does not elect to itemize deductions for such taxable year, the deduction under this section shall be equal to the deduction, not in excess of 1,000 ($2,000 in the case of a joint return)",
       "status": "match"
      },
      {
       "expect": "determined without regard to subsections (b)(1)(G)(ii), (b)(1)(I), and (d)(1)",
       "status": "match"
      },
      {
       "expect": "for the establishment of a new, or maintenance of an existing, donor advised fund",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    },
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/63",
     "title": "26 U.S. Code § 63",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "(4) the deduction provided in section 170(p)",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    },
    {
     "url": "https://www.govinfo.gov/content/pkg/PLAW-119publ21/html/PLAW-119publ21.htm",
     "title": "Public Law 119-21 (One Big Beautiful Bill Act), enrolled text",
     "publisher": "U.S. Government Publishing Office (govinfo)",
     "kind": "legislation",
     "official": true,
     "claims": [
      {
       "expect": "SEC. 70424. PERMANENT AND EXPANDED REINSTATEMENT OF PARTIAL DEDUCTION FOR CHARITABLE CONTRIBUTIONS OF INDIVIDUALS WHO DO NOT ELECT TO ITEMIZE",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "A QSS return is not a joint return: $1,000."
   ],
   "unsourced": null
  },
  "section_68": {
   "constant": "§68 limitation on the tax benefit of itemized deductions (OBBBA §70111)",
   "value": "2/37 of the lesser of itemized deductions and taxable income (+ itemized) over the 37% bracket start; taxable years after 2025",
   "engine": {
    "c": "backend/src/federal_tax.c ext_deduction",
    "js": null
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/68",
     "title": "26 U.S. Code § 68",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "shall be reduced by 2⁄37 of the lesser of- (1) such amount of itemized deductions, or (2) so much of the taxable income of the taxpayer for the taxable year (determined without regard to this section and increased by such amount of itemized deductions) as exceeds the dollar amount at which the 37 percent rate bracket under section 1 begins",
       "status": "match"
      },
      {
       "expect": "This section shall be applied after the application of any other limitation on the allowance of any itemized deduction",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    },
    {
     "url": "https://www.govinfo.gov/content/pkg/PLAW-119publ21/html/PLAW-119publ21.htm",
     "title": "Public Law 119-21 (One Big Beautiful Bill Act), enrolled text",
     "publisher": "U.S. Government Publishing Office (govinfo)",
     "kind": "legislation",
     "official": true,
     "claims": [
      {
       "expect": "(c) <<NOTE: 26 USC 68 note.>> Effective Date.--The amendments made by this section shall apply to taxable years beginning after December 31, 2025",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "Applies to ALL itemized deductions (not only charity): each itemized dollar in the 37% bracket saves 35 cents."
   ],
   "unsourced": null
  },
  "itemize_election": {
   "constant": "Itemize-vs-standard §63(b)/(e); MFS spouse-itemizes rule §63(c)(6)(A)",
   "value": "itemize by election (Schedule A line 18); MFS standard deduction 0 when either spouse itemizes",
   "engine": {
    "c": "backend/src/federal_tax.c ext_deduction",
    "js": null
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/63",
     "title": "26 U.S. Code § 63",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "Unless an individual makes an election under this subsection for the taxable year, no itemized deduction shall be allowed for the taxable year",
       "status": "match"
      },
      {
       "expect": "a married individual filing a separate return where either spouse itemizes deductions",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "Auto mode itemizes when Schedule A (after §68) exceeds the standard deduction plus §170(p): a larger deduction never raises federal tax."
   ],
   "unsourced": null
  },
  "blind_63f2": {
   "constant": "§63(f)(2) additional standard deduction for the blind",
   "value": "1,650 married / QSS; 2,050 unmarried (Rev. Proc. 2025-32 §4.14(3)); per blind filer, spouse on a joint return",
   "engine": {
    "c": "backend/src/federal_tax.c ext_deduction",
    "js": null
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/63",
     "title": "26 U.S. Code § 63",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "(2) Additional amount for blindThe taxpayer shall be entitled to an additional amount of $600- (A) for himself if he is blind at the close of the taxable year",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    },
    {
     "url": "https://www.irs.gov/pub/irs-drop/rp-25-32.pdf",
     "title": "Rev. Proc. 2025-32: 2026 inflation-adjusted items (incl. One Big Beautiful Bill amendments)",
     "publisher": "Internal Revenue Service",
     "kind": "guidance",
     "official": true,
     "claims": [
      {
       "expect": "the additional standard deduction amount under § 63(f) for the aged or the blind is $1,650. The additional standard deduction amount is increased to $2,050 if the individual is also unmarried and not a surviving spouse",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "The MFS case of a spouse with no income who is not a dependent (§63(f)(2)(B) via §151(b)) is not modelled: MFS counts the filer only."
   ],
   "unsourced": null
  },
  "qss": {
   "constant": "Qualifying surviving spouse §2(a): MFJ table and standard deduction, non-joint Pub 915 / senior thresholds",
   "value": "2 years after the year of death, dependent child, not remarried",
   "engine": {
    "c": "backend/src/federal_tax.c federal_qss_eligible, compose (FedInputExt.qss)",
    "js": null
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/2",
     "title": "26 U.S. Code § 2",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "whose spouse died during either of his two taxable years immediately preceding the taxable year",
       "status": "match"
      },
      {
       "expect": "is a son, stepson, daughter, or stepdaughter of the taxpayer",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    },
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/63",
     "title": "26 U.S. Code § 63",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "200 percent of the dollar amount in effect under subparagraph (C) for the taxable year in the case of- (i) a joint return, or (ii) a surviving spouse (as defined in section 2(a))",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    },
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/1411",
     "title": "26 U.S. Code § 1411",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "in the case of a taxpayer making a joint return under section 6013 or a surviving spouse (as defined in section 2(a)), $250,000",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    },
    {
     "url": "https://www.irs.gov/publications/p915",
     "title": "Publication 915 (2025), Social Security and Equivalent Railroad Retirement Benefits",
     "publisher": "Internal Revenue Service",
     "kind": "guidance",
     "official": true,
     "claims": [
      {
       "expect": "$25,000 if you are single, head of household, or qualifying surviving spouse",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "Not used by the planner (/api/simulate), whose widow path files single from the year after the death: POST /api/federal-tax and computeFederal only."
   ],
   "unsourced": null
  },
  "joint_life": {
   "constant": "RMD Joint and Last Survivor Table (spouse sole beneficiary, more than 10 years younger)",
   "value": "26 CFR 1.401(a)(9)-9(d), 121 x 121, generated",
   "engine": {
    "c": "backend/src/federal_tax.c rmd_joint_life_divisor; backend/src/rmd_joint_life_table.h (scripts/gen_rmd_joint_life_table.py)",
    "js": null
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.ecfr.gov/current/title-26/section-1.401(a)(9)-5",
     "title": "26 CFR 1.401(a)(9)-5",
     "publisher": "eCFR (Office of the Federal Register / GPO)",
     "kind": "regulation",
     "official": true,
     "claims": [
      {
       "expect": "If the employee's surviving spouse who is more than 10 years younger than the employee is the employee's sole beneficiary, then the applicable denominator is the joint and last survivor life expectancy for the employee and spouse",
       "status": "match"
      }
     ],
     "checked": "2026-09-28",
     "redirect_ok": true
    },
    {
     "url": "https://www.ecfr.gov/current/title-26/section-1.401(a)(9)-9",
     "title": "26 CFR 1.401(a)(9)-9",
     "publisher": "eCFR (Office of the Federal Register / GPO)",
     "kind": "regulation",
     "official": true,
     "claims": [
      {
       "expect": "The following table, referred to as the Joint and Last Survivor Table, is used for determining the joint and last survivor life expectancy of two individuals",
       "status": "match"
      },
      {
       "expect": "75 33.2 32.4 31.5 30.7 29.9 29.1 28.3 27.5 26.8 76",
       "status": "match"
      },
      {
       "expect": "73 33.4 32.6 31.7 30.9 30.1 29.4 28.6 27.9 27.2 74",
       "status": "match"
      },
      {
       "expect": "80 25.3 24.6 23.8 23.1 22.3 21.6 20.9 20.2 19.6 81",
       "status": "match"
      }
     ],
     "checked": "2026-09-28",
     "redirect_ok": true
    }
   ],
   "notes": [
    "eCFR prints cell (19, 35) blank; the generator fills it from its mirror (35, 19) = 68.0 and says so in the header. The printed table is symmetric only to within its 0.1 rounding ((2,5) 88.5 vs (5,2) 88.6); lookups use [owner][spouse] as printed. --check re-derives the header from eCFR."
   ],
   "unsourced": null
  },
  "qcd_split": {
   "constant": "One-time split-interest QCD §408(d)(8)(F)",
   "value": "55,000 (2026); once per lifetime; a QCD, so inside the annual 111,000",
   "engine": {
    "c": "backend/src/federal_tax.c federal_qcd_split_interest_limit, federal_qcd_split_interest_applied",
    "js": "frontend/js/calc/constants-2026.js (QCD_LIMITS_2026)"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/408",
     "title": "26 U.S. Code § 408",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "an election is not in effect under this subparagraph for a preceding taxable year",
       "status": "match"
      },
      {
       "expect": "If any dollar amount increased under clause (i) is not a multiple of $1,000, such dollar amount shall be rounded to the nearest multiple of $1,000",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    },
    {
     "url": "https://www.irs.gov/pub/irs-drop/n-25-67.pdf",
     "title": "Notice 2025-67: 2026 retirement plan limitations",
     "publisher": "Internal Revenue Service",
     "kind": "guidance",
     "official": true,
     "claims": [
      {
       "expect": "pursuant to a one-time election is increased from $54,000 to $55,000",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "That the split-interest distribution counts toward the annual §408(d)(8)(A) limit is the engine's reading of the statute: (F)(i) treats it as meeting (B)(i), i.e. as a qualified charitable distribution, and (A) limits the aggregate of such distributions per year."
   ],
   "unsourced": null
  },
  "72t_exceptions": {
   "constant": "§72(t)(2)(A) exceptions: disability, SEPP, separation from service at 55 (50 public safety), employer plans only",
   "value": "Form 5329 line 2",
   "engine": {
    "c": "backend/src/federal_tax.c ext_penalty",
    "js": null
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/72",
     "title": "26 U.S. Code § 72",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "attributable to the employee's being disabled within the meaning of subsection (m)(7)",
       "status": "match"
      },
      {
       "expect": "part of a series of substantially equal periodic payments (not less frequently than annually)",
       "status": "match"
      },
      {
       "expect": "made to an employee after separation from service after attainment of age 55",
       "status": "match"
      },
      {
       "expect": "Subparagraphs (A)(v) and (C) of paragraph (2) shall not apply to distributions from an individual retirement plan",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    },
    {
     "url": "https://www.irs.gov/retirement-plans/plan-participant-employee/retirement-topics-exceptions-to-tax-on-early-distributions",
     "title": "Retirement topics - Exceptions to tax on early distributions",
     "publisher": "Internal Revenue Service",
     "kind": "agency_page",
     "official": true,
     "claims": [
      {
       "expect": "the employee separates from service during or after the year the employee reaches age 55 (age 50 for public safety employees",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "The SEPP schedule itself (RMD / amortization / annuitization methods, Notice 2022-6) is not computed: the caller supplies the installment. Other exceptions (death, first home, medical, birth/adoption, emergency, domestic abuse, terminal illness, ...) are not modelled."
   ],
   "unsourced": null
  },
  "roth_408a": {
   "constant": "Roth distributions §408A(d): qualified distribution, ordering, conversion 5-year recapture",
   "value": "59½ or disabled + 5 taxable years; contributions, then conversions FIFO (taxable part first), then earnings",
   "engine": {
    "c": "backend/src/federal_tax.c ext_prepare, ext_penalty",
    "js": null
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/408A",
     "title": "26 U.S. Code § 408A",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "made on or after the date on which the individual attains age 59½",
       "status": "match"
      },
      {
       "expect": "within the 5-taxable year period beginning with the first taxable year for which the individual made a contribution to a Roth IRA",
       "status": "match"
      },
      {
       "expect": "such distribution is made within the 5-taxable year period beginning with the taxable year in which such contribution was made, then section 72(t) shall be applied as if such portion were includible in gross income",
       "status": "match"
      },
      {
       "expect": "Qualified rollover contributions to which paragraph (3) applies on a first-in, first-out basis",
       "status": "match"
      },
      {
       "expect": "shall be allocated first to the portion of such contribution required to be included in gross income",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "Engine convention for 59½: END-OF-YEAR age >= 60 (the §72(t) convention). Death, first-home and special-purpose distributions are not modelled; an unknown first-contribution year is treated as not qualified."
   ],
   "unsourced": null
  },
  "f8606_prorata": {
   "constant": "Form 8606 pro-rata basis §408(d)(2)",
   "value": "nontaxable = basis x amount / (Dec 31 value + distributions + conversions), ratio <= 1",
   "engine": {
    "c": "backend/src/federal_tax.c ext_prepare",
    "js": "frontend/js/calc/backdoor-roth.js"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/408",
     "title": "26 U.S. Code § 408",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "all individual retirement plans shall be treated as 1 contract, (B) all distributions during any taxable year shall be treated as 1 distribution",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "Employer-plan dollars carry no after-tax basis in the engine. The 8606 line 10 ratio is not rounded to 3 places (the form allows 'at least 3 places')."
   ],
   "unsourced": null
  },
  "missed_rmd_4974": {
   "constant": "Missed-RMD excise §4974 (SECURE 2.0)",
   "value": "25% of the shortfall; 10% when corrected in the correction window",
   "engine": {
    "c": "backend/src/federal_tax.c federal_missed_rmd_excise",
    "js": null
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/4974",
     "title": "26 U.S. Code § 4974",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "there is hereby imposed a tax equal to 25 percent of the amount by which such minimum required distribution exceeds the actual amount distributed during the taxable year",
       "status": "match"
      },
      {
       "expect": "the first sentence of subsection (a) shall be applied by substituting \"10 percent\" for \"25 percent\"",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "The §4974(d) reasonable-cause waiver is not modelled. The excise is not part of the Form 2210 tax (i2210: Schedule 2 line 8 \"additional tax on distributions only\")."
   ],
   "unsourced": null
  },
  "salt_sched_a": {
   "constant": "SALT cap as the engine applies it: MFS halving, 101% indexing, Schedule A line 5e worksheet",
   "value": "40,000 (2025) / 40,400 (2026), +1%/yr to 2029, 10,000 from 2030; reduced by 30% of MAGI over 500,000 / 505,000 (+1%/yr), floor 10,000; MFS half threshold, half amount",
   "engine": {
    "c": "backend/src/federal_tax.c federal_salt_cap",
    "js": "frontend/blog/2026-tax-brackets-did-not-revert-fire-planning/index.html (40,400)"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/164",
     "title": "26 U.S. Code § 164",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "shall not exceed the applicable limitation amount (half the applicable limitation amount in the case of a married individual filing a separate return)",
       "status": "match"
      },
      {
       "expect": "101 percent of the dollar amount in effect under this subparagraph for taxable years beginning in the preceding calendar year",
       "status": "match"
      },
      {
       "expect": "(half the threshold amount in the case of a married individual filing a separate return)",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    },
    {
     "url": "https://www.irs.gov/pub/irs-pdf/i1040sca.pdf",
     "title": "2025 Instructions for Schedule A (Form 1040)",
     "publisher": "Internal Revenue Service",
     "kind": "instructions",
     "official": true,
     "claims": [
      {
       "expect": "Multiply line 6 by 30% (0.30)",
       "status": "match"
      },
      {
       "expect": "Enter the larger of the amount on line 8 or $10,000",
       "status": "match"
      },
      {
       "expect": "half the amount on line 9 if married filing separately",
       "status": "match"
      },
      {
       "expect": "If you elect to itemize for state tax or other purposes even though your itemized deductions are less than your standard deduction, check the box on line 18",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "MAGI = AGI (no §§911/931/933 exclusions in the engine). The statute states no rounding for the 101% steps; the engine does not round."
   ],
   "unsourced": null
  },
  "estimated_2210": {
   "constant": "Form 2210 regular-method penalty: withholding split, period of underpayment, per-installment penalty",
   "value": "withholding 1/4 per due date; accrual to the earlier of payment and the return due date; simple interest per rate quarter",
   "engine": {
    "c": "backend/src/federal_tax.c federal_est_compute",
    "js": "frontend/js/calc/estimated-tax-2026.js computeUnderpayment"
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.law.cornell.edu/uscode/text/26/6654",
     "title": "26 U.S. Code § 6654",
     "publisher": "Cornell Legal Information Institute (text of the U.S. Code, Title 26)",
     "kind": "statute",
     "official": true,
     "claims": [
      {
       "expect": "an equal part of such amount shall be deemed paid on each due date",
       "status": "match"
      },
      {
       "expect": "the 15th day of the 4th month following the close of the taxable year",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    },
    {
     "url": "https://www.irs.gov/pub/irs-pdf/i2210.pdf",
     "title": "Instructions for Form 2210 (2025)",
     "publisher": "Internal Revenue Service",
     "kind": "instructions",
     "official": true,
     "claims": [
      {
       "expect": "The penalty is figured separately for each installment due date",
       "status": "match"
      },
      {
       "expect": "substitute 110% for 100% in (2) above",
       "status": "match"
      },
      {
       "expect": "Line 8 (additional tax on distributions only)",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "The underpayment calculator computes through the JS module, the JS copy of federal_est_compute (drift gate EST-module / EST-page). The annualized income method (Schedule AI), §6654(e)(3) waivers and the farmer/fisher 66⅔% rule are not modelled (stated on the page)."
   ],
   "unsourced": null
  },
  "form_lines_schedules": {
   "constant": "Line labels of Schedule A, Forms 8606, 5329 and 2210 (TY2025 forms; TY2026 not yet published)",
   "value": "Schedule A 4, 5d, 5e, 10, 14, 17; 8606 11, 13, 14, 25c; 5329 1, 2, 55; 2210 9, 17, 19",
   "engine": {
    "c": "backend/src/federal_tax.c ext_trace",
    "js": null
   },
   "status": "verified",
   "sources": [
    {
     "url": "https://www.irs.gov/pub/irs-pdf/f1040sa.pdf",
     "title": "Schedule A (Form 1040) 2025",
     "publisher": "Internal Revenue Service",
     "kind": "instructions",
     "official": true,
     "claims": [
      {
       "expect": "Subtract line 3 from line 1. If line 3 is more than line 1, enter -0-",
       "status": "match"
      },
      {
       "expect": "Add lines 5a through 5c",
       "status": "match"
      },
      {
       "expect": "Enter the smaller of line 5d or $40,000 ($20,000 if married filing separately)",
       "status": "match"
      },
      {
       "expect": "Add lines 8e and 9",
       "status": "match"
      },
      {
       "expect": "Add lines 11 through 13",
       "status": "match"
      },
      {
       "expect": "Add the amounts in the far right column for lines 4 through 16",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    },
    {
     "url": "https://www.irs.gov/pub/irs-pdf/f8606.pdf",
     "title": "Form 8606 (2025)",
     "publisher": "Internal Revenue Service",
     "kind": "instructions",
     "official": true,
     "claims": [
      {
       "expect": "This is the nontaxable portion of the amount you converted to Roth IRAs",
       "status": "match"
      },
      {
       "expect": "Add lines 11 and 12. This is the nontaxable portion of all your distributions",
       "status": "match"
      },
      {
       "expect": "c Taxable amount. Subtract line 25b from line 25a",
       "status": "match"
      },
      {
       "expect": "Subtract line 13 from line 3. This is your total basis in traditional IRAs for 2025 and earlier years",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    },
    {
     "url": "https://www.irs.gov/pub/irs-pdf/f5329.pdf",
     "title": "Form 5329 (2025)",
     "publisher": "Internal Revenue Service",
     "kind": "instructions",
     "official": true,
     "claims": [
      {
       "expect": "Early distributions included on line 1 that are not subject to the additional tax",
       "status": "match"
      },
      {
       "expect": "55 Add lines 54a and 54b. Include the total on Schedule 2 (Form 1040), line 8",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    },
    {
     "url": "https://www.irs.gov/pub/irs-pdf/f2210.pdf",
     "title": "Form 2210 (2025)",
     "publisher": "Internal Revenue Service",
     "kind": "instructions",
     "official": true,
     "claims": [
      {
       "expect": "Required annual payment. Enter the smaller of line 5 or line 8",
       "status": "match"
      },
      {
       "expect": "19 Penalty. Enter the total penalty from line 14 of the Worksheet for Form 2210, Part III, Section B-Figure the Penalty",
       "status": "match"
      },
      {
       "expect": "Required installments. If box C in Part II applies",
       "status": "match"
      }
     ],
     "checked": "2026-09-28"
    }
   ],
   "notes": [
    "The engine's own ids for amounts the TY2025 forms have no line for (the §68 reduction, the blind addition, the itemize flag, the §170(p) deduction, the RMD) say so in their labels."
   ],
   "unsourced": null
  }
 },
 "unsourced": [
  {
   "item": "NY and VT community rating (age factor 1.0 for all adults)",
   "where": "aca_bridge_optimizer.c is_community_rated(); constants-2026.js COMMUNITY_RATED_STATES",
   "reason": "State law (NY Ins. Law §3231 / 11 NYCRR 360; 8 V.S.A. §4080a). The CMS Market Rating Reforms page renders its state table client-side, so no checkable quote was captured."
  },
  {
   "item": "CHRONIC_OOP bands 3,000 / 8,000 / 18,000",
   "where": "aca_bridge_optimizer.c CHRONIC_OOP; constants-2026.js CHRONIC_OOP_BANDS",
   "reason": "QuantCalc model parameters, not an official figure; disclosed as such on /methodology."
  },
  {
   "item": "SS spousal/survivor factors 0.285 / 0.825; SSA 2022 period life table",
   "where": "frontend/js/calc/ss-spousal-survivor.js; frontend/js/calc/annuity-payout.js",
   "reason": "Social Security benefit rules and actuarial tables, not tax constants; outside this file."
  }
 ]
}