State tax docs / Updates
Updates, versioning and the changelog
State rules change every year, and most of the change lands between October and January, when states publish the next year's indexed brackets, deductions and caps and their new forms. This page describes how the engine follows those changes.
The annual cycle
- Monitoring (continuous, heaviest October to January). The weekly source check fetches every cited page and flags any whose checked figure has changed or disappeared. A changed figure is the usual first sign of a new year's value.
- Research. Each flagged rule is re-read at its official source. Where a state has not yet published a figure the engine keeps the latest published value and marks it as a prior-year proxy on the state page.
- Engine change. The value is changed in the engine source with its citation beside it, and a test pins the new value.
- Gates. The engine suite, the golden scenarios and the docs gate must all pass: the dump is regenerated, the pages are regenerated, and every source's checked value must match the engine.
- Release. The engine, the API and these pages ship together, and the change is recorded below.
Versioning
The engine is at version 1.4.0 for tax year 2026. Each API response carries
engineVersion and taxYear, and so does the engine configuration download. Versions are semantic: a major version
changes the meaning of an input or configuration field; a minor version adds inputs or rules, and requests that do not use them return
identical results (a test holds this over a large random set of requests in all 51 jurisdictions); a patch corrects data or a rule and
can move results, and says which. A new tax year is a new configuration, not an edit of the previous one; corrections within a year are
listed below with their date.
Changelog
| Date | States | Change |
|---|---|---|
| 2026-09-27 | DC, ID, NM, OK, SC | Engine 1.4.0: gaps left by the 1.3.0 check. DC, Idaho and New Mexico include the federal additional standard deduction at 65 ($2,050 unmarried / $1,650 married); New Mexico's exemption for filers 65 or older (up to $8,000 each, stepped down by income) and its low- and middle-income exemption (up to $2,500 per exemption, any age); Idaho allows the federal senior deduction ($6,000 per filer 65 or older, reduced 6% above $75,000 / $150,000 joint); Oklahoma heads of household use the joint rate schedule; South Carolina heads of household get their own $22,500 deduction, phased out from $60,000. With pensionPublicSsCovered: false, Oklahoma excludes a civil-service (CSRS) pension in full and Idaho applies its civil-service retirement deduction at 65. |
| 2026-09-27 | ME, MN, MO, OK, VT, WI | Engine 1.3.0: gaps found by the 1.2.0 source check. Vermont heads of household get their own deduction ($11,450, the latest published figure) and rate schedule; Maine, Missouri and Minnesota include the additional standard deduction at 65 ($2,050 / $1,650 in Maine and Missouri, $2,000 / $1,600 in Minnesota), and Maine's personal exemption phases out above $341,000 of income ($409,150 joint); Oklahoma's extra $1,000 exemption for filers 65 or older with federal AGI up to $15,000 ($25,000 joint); Wisconsin's married-filing-separately schedule ($10,080 / $34,630 / $221,820). New optional API input pensionPublicSsCovered: false applies Minnesota's public pension subtraction and Vermont's CSRS exclusion to a pension earned without Social Security coverage. |
| 2026-09-27 | AZ, CO, CT, DC, GA, ID, LA, MA, MD, ME, MN, MO, MS, MT, ND, NE, NJ, NM, NY, OH, OK, UT, VA, VT, WI, WV | Engine 1.2.0: 58 corrections found by checking every rule against its official source. 2026 standard deductions and thresholds (GA, ME, MD, ND, WI); head-of-household schedules and deductions where the state has its own (NY, NE, MT, NM, ID, MD, NJ, MO, DC, MA, MS, WI); personal exemptions (OK, VA, WI, NJ 65+, MD tiers, OH tiers); Maine's 2% surcharge and Vermont's 3% minimum tax; public pensions in AZ, LA, MA and WV; NJ's pension exclusion bands on the whole pension; Ohio's $332 base amount; CT's step-table exemption phase-out and conversion treatment; per-spouse caps in CO and a per-spouse 0% band in MS; West Virginia's senior modification net of Social Security. The API now refuses an unrecognised filingStatus with 400 instead of treating it as a joint return. |
| 2026-09-27 | DE | Engine 1.1.0 data correction: Delaware's extra $110 personal credit starts at age 60, not 65 (moves Delaware results for filers aged 60 to 64). |
| 2026-09-27 | all | Engine 1.1.0: each spouse's own age on joint returns (every age-conditioned rule evaluated per person where the state applies it per person), military retirement pay as its own income type with each state's rule, wages as an earned-income component (Georgia, Wisconsin, Ohio rules), and a per-person account of exclusions. Requests that use none of the new inputs return identical results. |
| 2026-09-27 | MO | Missouri: short-term capital gains are exempt as well as long-term gains (RSMo 143.121.3(14)(a) subtracts all capital gain reported federally). |
| 2026-08-13 | all | Per-spouse attribution: an inconsistent spouse split can no longer exclude more than the household's eligible dollars. |
| 2026-08-13 | AL, AR, DE, LA, OK, SC, MO | Per-spouse attribution on joint returns: where the retirement exclusion is per taxpayer, each spouse's own dollars draw only that spouse's cap when a split is supplied. Calls without a split are unchanged. |
| 2026-08-13 | MO | Missouri: public-pension dollars left taxable by the Social Security offset no longer draw the private-pension exemption. |
| 2026-08-13 | AL, AR, DE, LA, ME, MO, OK, SC, VA, CO | Roth conversions against retirement exclusions settled state by state (drawn in AL, DE, LA, OK, SC; not drawn in AR, ME, MO, CO); Virginia's age deduction applies against any income; Missouri's private-pension income reduction is subtractive and Missouri's public-pension exemption is reduced by taxable Social Security. |
| 2026-07-11 | MO, KS | Public pensions: Missouri exempts them up to the maximum Social Security benefit per taxpayer; Kansas exempts KPERS, federal civil service and military pensions in full. |
| 2026-07-11 | RI | Rhode Island: the pension modification applies to pension and annuity income only, not IRA distributions. |
| 2026-07-11 | MD | Maryland: the 65+ pension exclusion applies to employer-plan income only and is reduced by Social Security received. |
| 2026-07-11 | AL | Alabama: employer (defined-benefit) pensions fully exempt; IRA and 401(k) dollars keep the $6,000 65+ exclusion. |
| 2026-07-10 | MT | Montana: the state base starts from federal taxable income when the caller supplies it. |
| 2026-07-10 | CO, ND, IA | Colorado, North Dakota and Iowa: the state base starts from federal taxable income when the caller supplies it. |
| 2026-07-10 | NY, CT | New York tax-benefit recapture and Connecticut's 2% phase-out add-back and benefit recapture added. |
| 2026-07-10 | IN, MD | Indiana and Maryland county income taxes added, with a default average rate and a per-request override. |
| 2026-07-10 | AL, OR | Alabama and Oregon federal-income-tax deductions added (applied when the caller supplies federal tax). |
| 2026-07-10 | NY, HI | Public-pension input added: New York exempts New York and federal government pensions; Hawaii exempts employer-funded pensions. |
| 2026-07-10 | CT, ME | Gross Social Security accepted as an input: Connecticut's 25%-of-gross rule and Maine's pension offset compute exactly. |
| 2026-07-09 | MA, CA | Out-year scaling: the Massachusetts surtax threshold is indexed; California's is fixed. |
| 2026-07-09 | MT | Montana: long-term gains taxed on the 3.0%/4.1% capital-gains schedule instead of ordinary rates. |
| 2026-07-09 | AR, DE, VA, MS, MO | Married filing separately uses the single schedule unscaled in states with one schedule for every filing status. |
| 2026-07-09 | HI, ID, MA, MN, MS, NM, PA, RI, WI | 2026 corrections against state sources for Hawaii, Idaho, Massachusetts, Minnesota, Mississippi, New Mexico, Pennsylvania, Rhode Island and Wisconsin. |
| 2026-07-09 | CA, CO, LA, MO, NJ, NY, OH, OR, VT, WV | 2026 corrections against state sources for California, Colorado, Louisiana, Missouri, New Jersey, New York, Ohio, Oregon, Vermont and West Virginia. |
| 2026-07-09 | AR, AZ, CT, DE, KY, MD, MI, ND, NE, UT, WA | 2026 corrections against state sources for Arkansas, Arizona, Connecticut, Delaware, Kentucky, Maryland, Michigan, North Dakota, Nebraska, Utah and Washington. |
| 2026-07-09 | AL, DC, GA, IL, IN, KS, ME, MT, NC, SC, VA | 2026 corrections against state sources for Alabama, DC, Georgia, Illinois, Indiana, Kansas, Maine, Montana, North Carolina, South Carolina and Virginia. |
| 2026-07-09 | AZ | Arizona: standard deduction follows the 2026 federal amount. |
| 2026-07-06 | all | 2026 flat-state rates refreshed; California and DC standard deductions updated. |
| 2026-07-06 | all | Real 2026 bracket schedules for every progressive state (four regional batches, replacing a generic template). |
| 2026-07-06 | all | Retirement-income exclusions for all 51 jurisdictions, with age tiers and income limits. |
| 2026-07-05 | all | Per-state pension, IRA and Roth-conversion treatment added. |
| 2026-07-05 | CO, VT | Colorado Social Security follows the enacted HB24-1142 rule; Vermont uses the Act 71 thresholds. |
| 2026-07-05 | all | Per-state Social Security treatment for 2026 (nine statutory formulas). |