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Louisiana state income tax: engine rules, 2026

How the QuantCalc engine computes Louisiana tax for tax year 2026, rule by rule, with the official source for each rule. Verification status: Worksheet-tested (what this means).

On this page: How the tax is computed · Rate schedule · Deductions, exemptions and credits · Social Security · IRA, 401(k) and private pensions · Public pensions · Military retirement pay · Roth conversions · Capital gains · Blindness and disability · Part-year and nonresident returns · Worked examples · After 2026 · Not calculated · Verification. Machine-readable: this state's entry in the engine config and the provenance file (key LA).

How the tax is computed

Every step the engine takes for Louisiana, in the order it takes them. Steps marked with a filing status or household type apply only there. Each step links the section below that carries Louisiana's figures and the official sources for it; the calculation order page describes every step for all jurisdictions.

What each filing status gets, read back from the engine for a household with $1 of income (so below every phase-out and income test):

SingleMarried filing jointlyMarried filing separatelyHead of household
Rate schedule usedsingle schedulejoint schedulejoint schedule, thresholds halvedsingle schedule
Top rate3% flat3% flat3% flat3% flat
Standard deduction, under 65nonenonenonenone
Standard deduction at 70 (joint: both 70)nonenonenonenone
Personal exemptionnonenonenonenone
Age subtractions at 70 (joint: both 70)nonenonenonenone
  1. Per-person mode joint returns with the spouse's age given On a joint return with the spouse's age given, every age test the state applies per taxpayer is evaluated for each spouse at their own age. Without it one household age applies to both.
    engine step (compute_state_tax_detail). Engine convention, no external source: The engine cannot know the second spouse's age unless told.
  2. Blindness and disability, per person only when the caller says a person is blind or disabled The filer is person one; the spouse counts only on a joint return and only when the caller says so (there is no household convention as for age). Where a state lets a disabled person (and, where it says so, a blind one, or one whose spouse is disabled) qualify for its general retirement exclusion before the age, that person is treated as having reached the age for that exclusion only. Of the 42 taxing jurisdictions, these have a blind amount: Arizona, Arkansas, California, Colorado, Delaware, the District of Columbia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, New Jersey, New Mexico, North Dakota, Oklahoma, Oregon, Utah, Vermont and Virginia; these have none: Alabama, Connecticut, Georgia, Louisiana, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, South Carolina, West Virginia and Wisconsin. A disability route is calculated in Arkansas, the District of Columbia, Georgia, Hawaii, Idaho, Iowa, Maryland, Michigan, New Jersey, Oregon and West Virginia.
    engine step (compute_state_tax_detail). Engine convention, no external source: Who is blind or disabled is the caller's statement; the engine has no household convention for it.
  3. Rate schedule and standard deduction by filing status Single uses the single schedule and deduction; married filing jointly the joint ones. Head of household and married filing separately follow the two steps below.
    Louisiana's values · engine step (select_brackets). Sources (Rate schedule): 2026 Estimated Tax Voucher for Individuals, Instructions (IT-540ES) (checked 2026-10-12); Revenue Information Bulletin 25-012: Louisiana Individual Income Tax Reform (checked 2026-10-12)
  4. Married filing separately Where the state publishes its own separate schedule, that one (with half the joint deduction unless a separate deduction is set). Where one schedule applies to every status, that schedule unscaled with the single deduction. Otherwise the joint schedule with every threshold and the deduction halved (computed as the joint tax on twice the income, halved).
    Louisiana's values · engine step (select_brackets). Sources (Rate schedule): 2026 Estimated Tax Voucher for Individuals, Instructions (IT-540ES) (checked 2026-10-12); Revenue Information Bulletin 25-012: Louisiana Individual Income Tax Reform (checked 2026-10-12)
  5. Head of household The state's head-of-household schedule where it has one, else the single schedule; the head-of-household deduction where set, else the single deduction.
    Louisiana's values · engine step (select_brackets). Sources (Rate schedule): 2026 Estimated Tax Voucher for Individuals, Instructions (IT-540ES) (checked 2026-10-12); Revenue Information Bulletin 25-012: Louisiana Individual Income Tax Reform (checked 2026-10-12)
  6. The income total every income test uses Other ordinary income + retirement distributions (before any exclusion) + conversion + federally taxable Social Security + long-term gains + Railroad Retirement Tier 2. It stands in for federal adjusted gross income in every threshold, cliff and phase-out below; state subtractions do not reduce it.
    engine step (compute_state_tax_detail). Engine convention, no external source: The inputs are the federal AGI components, so their sum is federal AGI for these income types.
  7. No tax without a federal return When the household's federal gross income (the income total, Social Security only in its taxable part) is under the federal filing threshold for the status (the basic standard deduction plus the aged amount per person 65 or older; a fixed amount on a separate return), the state tax is zero.
    Louisiana's values · engine step (compute_state_tax_detail). Sources (Deductions, exemptions and credits): Revenue Information Bulletin 26-019: Inflation Adjustment to Standard Deduction and Retirement Income Exemption (checked 2026-10-12); Revenue Information Bulletin 25-012: Louisiana Individual Income Tax Reform (checked 2026-10-12); 2025 IT-540 instructions (checked 2026-10-12); 2025 IT-540 instructions (line 13) (checked 2026-10-12); Rev. Proc. 2025-32 (2026 inflation adjustments) (checked 2026-10-12)
  8. Attributing income to each spouse joint returns with each spouse's own amounts given With a caller's split (the API's spouse object), each spouse's own distributions (employer-plan money included), pension, public pension, conversion, wages and military pay; spouse 2's shares are clamped into the household totals and spouse 1 gets the rest. Without a split, in per-person mode, every item is divided 50/50. Social Security is divided by each spouse's own gross benefits where the caller gives spouse.socialSecurityGross, else 50/50; other ordinary income and gains are always divided 50/50 where a rule needs a per-person amount. The split is used only where a state's rule is per taxpayer; household totals stay authoritative for the base and the income tests.
    engine step (compute_state_tax_detail). Engine convention, no external source: Equal attribution is the neutral split when the owner of a dollar is not known.
  9. Disability pay only when the caller gives the person facts (a civil service annuity, disability pay, Social Security disability, survivor benefits, an IRA basis or an exception) Each person's disability pay (the caller's disabilityIncome, part of the pension income) is excluded up to the state's cap (all of it where there is none), for a totally and permanently disabled person where the state requires it and below the age where there is one; on a joint return without per-person amounts the cap is doubled only when a second person can qualify (the spouse also said to be disabled where the state requires it). Where the state reduces it, the total is reduced dollar for dollar by the return's income over the threshold (one threshold per return; the separate-return threshold where there is one). The excluded dollars leave the base before any retirement exclusion. Where the state reads it, the plan's minimum retirement age (when given) replaces the age at which the pay stops being excluded.
    Louisiana's values · engine step (compute_state_tax_detail). Sources (Blindness and disability): Louisiana Department of Revenue: IT540i-WEB-2025-Revised-7-26.pdf (checked 2026-10-12)
  10. Keeping the per-spouse shares inside the household joint returns with each spouse's own amounts given After the public-pension and employer-pension carve-outs, if the two spouses' remaining shares add up to more than the household's exclusion-eligible distributions (an inconsistent split), spouse 1's share is reduced so they do not.
    engine step (compute_state_tax_detail). Engine convention, no external source: Input normalisation.
  11. Military retirement pay The state's military rule runs first, on military pay alone, per taxpayer: each spouse's own pay at their own age when attributed, otherwise half each at the household age on a joint return. Exempt dollars leave the base; the rest become pension dollars for the general retirement rules. Where the state lets a disabled retiree qualify at any age, a disabled person is treated as having reached the rule's age.
    Louisiana's values · engine step (compute_state_tax_detail). Sources (Military retirement pay): Is there a list of retirement system benefits that may be excluded from louisiana income tax (checked 2026-10-12)
  12. One taxpayer's military exemption Exempt: all of it (below the age split, up to the younger cap). Capped: up to the cap for the age tier, plus the earned-income bonus below the age split when the taxpayer's own wages exceed the threshold, less the taxpayer's own Social Security where the rule says so. Percentage: the percentage (below the age split, up to the younger cap). Then the income limit: above it the exemption is lost, or phased out over the range where one is set.
    Louisiana's values · engine step (military_exempt_one). Sources (Military retirement pay): Is there a list of retirement system benefits that may be excluded from louisiana income tax (checked 2026-10-12)
  13. Capital-loss deduction off the base The deduction comes off the other ordinary income (negative income, as Form 1040 line 7a is), so the base and every state-AGI figure summed from it carry it; WI no more than Wisconsin ordinary income (Schedule WD line 28(c)). States whose base is federal taxable income (with the caller's figure) already have it there and take it only once. Engine 1.13.1: the allowed rental loss comes off the same way, on its own line (rental_loss_deduction).
    Louisiana's values · engine step (compute_state_tax_detail). Sources (Capital gains): Revenue Information Bulletin 25-012: Louisiana Individual Income Tax Reform (checked 2026-10-12); 2025 Louisiana Resident Income Tax Return Instructions (IT-540) (checked 2026-10-12); 2025 IT-540 Instructions (checked 2026-10-12); 2025 Schedule D (Form 1040), Capital Gains and Losses (checked 2026-10-12)
  14. Public pension exemption Public-pension dollars leave the base, uncapped or up to the per-taxpayer cap (each spouse's own public pension against their own cap when attributed), without using up the general exclusion the remaining distributions may claim. Capped-out public dollars stay taxable and cannot draw the private exclusion.
    Louisiana's values · engine step (compute_state_tax_detail). Sources (Public pensions): 2025 Louisiana Resident Income Tax Return Instructions (IT-540) (checked 2026-10-12); Is there a list of retirement system benefits that may be excluded from louisiana income tax (checked 2026-10-12)
  15. Social Security exempt None of the federally taxable benefit enters the base.
    Louisiana's values · engine step (ss_amount_in_state_base). Sources (Social Security): 2025 Louisiana Resident Income Tax Return Instructions (IT-540) (checked 2026-10-12)
  16. Does a conversion draw the retirement cap? Where the state lets a conversion draw the capped exclusion, and the filer is at or above the conversion age (the state's own pooling age where it has one; any age for a disabled person where the state says so), the conversion is pooled with distributions against the cap. A spouse who elects not to claim the exclusion draws none of it.
    Louisiana's values · engine step (compute_state_tax_detail). Sources (Roth conversions): 2025 Louisiana Resident Income Tax Return Instructions (IT-540) (checked 2026-10-12); Louisiana Administrative Code, Title 61, Part I, §1311 (Annual Retirement Income Exemption for Individuals 65 or Older) (checked 2026-10-12)
  17. Retirement exclusion per spouse (both ages known) joint returns with the spouse's age given Full-exclusion states exclude each qualifying spouse's own dollars. Capped states give each spouse the single cap for their own age against their own eligible dollars (pension dollars only where the exclusion is pension-only; employer dollars only below the IRA age), less their military exclusion and their own Social Security offset (by the spouse's stated gross benefits, else half). Per-return states (and the pooled-if-both-qualify rule when both qualify) apply the joint cap to the couple's pooled eligible dollars when either spouse qualifies. The income tests then apply once to the summed deduction.
    Louisiana's values · engine step (compute_state_tax_detail). Sources (IRA, 401(k) and private pensions): Revenue Information Bulletin 26-019: Inflation Adjustment to Standard Deduction and Retirement Income Exemption (checked 2026-10-12); 2025 Louisiana Resident Income Tax Return Instructions (IT-540) (checked 2026-10-12); Revenue Information Bulletin 25-012: Louisiana Individual Income Tax Reform (checked 2026-10-12)
  18. Conversion pooled with distributions The conversion joins the distributions against the one cap (with a spouse split in a per-taxpayer state, each spouse's own distributions and conversion against that spouse's cap). Nothing of the conversion is added separately.
    Louisiana's values · engine step (compute_state_tax_detail). Sources (Roth conversions): 2025 Louisiana Resident Income Tax Return Instructions (IT-540) (checked 2026-10-12); Louisiana Administrative Code, Title 61, Part I, §1311 (Annual Retirement Income Exemption for Individuals 65 or Older) (checked 2026-10-12)
  19. Retirement exclusion (household) The distributions eligible for the exclusion go through the exclusion below. Taxable public-pension dollars left by a cap are not eligible; below the IRA age only employer-plan dollars are.
    Louisiana's values · engine step (compute_state_tax_detail). Sources (IRA, 401(k) and private pensions): Revenue Information Bulletin 26-019: Inflation Adjustment to Standard Deduction and Retirement Income Exemption (checked 2026-10-12); 2025 Louisiana Resident Income Tax Return Instructions (IT-540) (checked 2026-10-12); Revenue Information Bulletin 25-012: Louisiana Individual Income Tax Reform (checked 2026-10-12)
  20. Retirement exclusion per spouse (declared split) joint returns with each spouse's own amounts given With a spouse split in a per-taxpayer state, each spouse's own eligible dollars draw that spouse's single cap (less their military exclusion); an income limit then applies once to the sum.
    Louisiana's values · engine step (compute_state_tax_detail). Sources (IRA, 401(k) and private pensions): Revenue Information Bulletin 26-019: Inflation Adjustment to Standard Deduction and Retirement Income Exemption (checked 2026-10-12); 2025 Louisiana Resident Income Tax Return Instructions (IT-540) (checked 2026-10-12); Revenue Information Bulletin 25-012: Louisiana Individual Income Tax Reform (checked 2026-10-12)
  21. Conversion taxed or exempt In full-exclusion states a conversion is exempt at the qualifying age (at any age where the state says so). Elsewhere, unless pooled above, it is ordinary income taxed in full.
    Louisiana's values · engine step (compute_state_tax_detail). Sources (Roth conversions): 2025 Louisiana Resident Income Tax Return Instructions (IT-540) (checked 2026-10-12); Louisiana Administrative Code, Title 61, Part I, §1311 (Annual Retirement Income Exemption for Individuals 65 or Older) (checked 2026-10-12)
  22. Cap by age tier The full cap at or above the exclusion age, the lower cap at or above the partial age, otherwise none. Joint returns use the joint cap; every other status the single cap.
    Louisiana's values · engine step (retirement_distributions_in_state_base). Sources (IRA, 401(k) and private pensions): Revenue Information Bulletin 26-019: Inflation Adjustment to Standard Deduction and Retirement Income Exemption (checked 2026-10-12); 2025 Louisiana Resident Income Tax Return Instructions (IT-540) (checked 2026-10-12); Revenue Information Bulletin 25-012: Louisiana Individual Income Tax Reform (checked 2026-10-12)
  23. The capped deduction Deduction = the smaller of the eligible distributions and the cap, then reduced by the income limit above; the rest of the distributions stays in the base.
    Louisiana's values · engine step (retirement_distributions_in_state_base). Sources (IRA, 401(k) and private pensions): Revenue Information Bulletin 26-019: Inflation Adjustment to Standard Deduction and Retirement Income Exemption (checked 2026-10-12); 2025 Louisiana Resident Income Tax Return Instructions (IT-540) (checked 2026-10-12); Revenue Information Bulletin 25-012: Louisiana Individual Income Tax Reform (checked 2026-10-12)
  24. One taxpayer's cap joint returns with the spouse's age given For per-spouse calculations, each spouse's cap is the single-column cap for their age tier.
    Louisiana's values · engine step (per_taxpayer_cap_single). Sources (IRA, 401(k) and private pensions): Revenue Information Bulletin 26-019: Inflation Adjustment to Standard Deduction and Retirement Income Exemption (checked 2026-10-12); 2025 Louisiana Resident Income Tax Return Instructions (IT-540) (checked 2026-10-12); Revenue Information Bulletin 25-012: Louisiana Individual Income Tax Reform (checked 2026-10-12)
  25. Long-term gains in the base Where gains are taxed as ordinary income: net long-term gain less the flat exclusion (never below zero), times the inclusion share. Elsewhere none enters.
    Louisiana's values · engine step (compute_state_tax_detail). Sources (Capital gains): Revenue Information Bulletin 25-012: Louisiana Individual Income Tax Reform (checked 2026-10-12); 2025 Louisiana Resident Income Tax Return Instructions (IT-540) (checked 2026-10-12); 2025 IT-540 Instructions (checked 2026-10-12); 2025 Schedule D (Form 1040), Capital Gains and Losses (checked 2026-10-12)
  26. State taxable income Other ordinary income + Social Security, retirement income, conversion and gains left in the base − standard deduction − personal exemption − age subtractions.
    engine step (compute_state_tax_detail). Engine convention, no external source: The order of subtraction follows the state forms; each amount is sourced at its own step.
  27. No tax at or below zero State taxable income at or below zero returns a tax of 0 (credits are not refundable), unless the state has a tax computed apart from taxable income that still applies (next step).
    engine step (compute_state_tax_detail). Engine convention, no external source: Every credit the engine carries is nonrefundable, so nothing below can make a zero tax negative; each credit is sourced at its own step.
  28. Separate-return scaling married filing separately For the halved-joint rule, taxable income is doubled before the schedule and the result halved.
    Louisiana's values · engine step (compute_state_tax_detail). Sources (Rate schedule): 2026 Estimated Tax Voucher for Individuals, Instructions (IT-540ES) (checked 2026-10-12); Revenue Information Bulletin 25-012: Louisiana Individual Income Tax Reform (checked 2026-10-12)
  29. The rate schedule Each bracket's rate on the part of taxable income inside it, summed. No rounding: the result is carried in full precision.
    Louisiana's values · engine step (apply_state_brackets). Sources (Rate schedule): 2026 Estimated Tax Voucher for Individuals, Instructions (IT-540ES) (checked 2026-10-12); Revenue Information Bulletin 25-012: Louisiana Individual Income Tax Reform (checked 2026-10-12)
  30. Credits cannot make the tax negative The credits are subtracted and the result floored at zero.
    engine step (compute_state_tax_detail). Engine convention, no external source: Every credit the engine carries is nonrefundable; each credit is sourced at its own step.
  31. Qualifying surviving spouse qualifying surviving spouse returns A qualifying surviving spouse (filingStatus qss) is one person on the return, taxed from the single figures with the state's own treatment of the status laid over them: where the state says so, the joint rate schedule, the joint standard deduction, the joint personal exemption, the joint income limits and phase-outs (only those the state sets for joint returns), the married 65+ and blindness amounts, or the head-of-household return; where the state gives the status nothing of its own, the single return. The federal figures the engine derives for the status are the federal qualifying-surviving-spouse ones (the joint standard deduction, the married 65+ amount).
    Louisiana's values · engine step (state_tax_effective_config). Sources (Rate schedule): 2026 Estimated Tax Voucher for Individuals, Instructions (IT-540ES) (checked 2026-10-12); Revenue Information Bulletin 25-012: Louisiana Individual Income Tax Reform (checked 2026-10-12)
  32. Railroad Retirement benefits only when the caller gives Railroad Retirement benefits Railroad Retirement benefits are never taxed by a state (45 U.S.C. §231m). Tier 2 (railroadRetirementTier2) is in the income total the tests use but never in the base. Tier 1 (railroadRetirementTier1) is a part of the gross benefits (socialSecurityGross); its share of the taxable benefits is taken out of the Social Security every state rule sees, so a state that taxes Social Security never reaches it. Where a state's worksheet says so, the benefits reduce a retirement cap or subtraction (ID, IN, MD, ME, MN: both tiers; MI: the taxable railroad benefits); Minnesota's and Utah's Social Security rules test an income without them, Minnesota's, New Jersey's and California's retirement income tests an income without Tier 2; Ohio and Delaware test their own AGI everywhere, which never holds the benefits.
    Louisiana's values · engine step (compute_state_tax_detail). Sources (Social Security): 2025 Louisiana Resident Income Tax Return Instructions (IT-540) (checked 2026-10-12)
  33. The capital-loss deduction the state allows With a net capital loss (capitalLoss): the smaller of the loss and the state's limit (the federal $3,000 / $1,500 where the state follows the federal return; MA $2,000, and no more than the interest and dividends); AL the loss less the part carried in, unlimited; PA and NJ none. It comes off the income total the income tests use (and the Social Security worksheets' income); the gross-income filing test (LA) reads the total before it. Engine 1.13.1: with a rental loss (rentalNetIncome below 0, the federal Schedule E line 26 amount) the state allows, the whole loss where the state starts from federal AGI or follows the federal schedule, none in PA and NJ (rental_loss_no_offset): it comes off the same income the same way; a rental profit is other ordinary income.
    Louisiana's values · engine step (compute_state_tax_detail). Sources (Capital gains): Revenue Information Bulletin 25-012: Louisiana Individual Income Tax Reform (checked 2026-10-12); 2025 Louisiana Resident Income Tax Return Instructions (IT-540) (checked 2026-10-12); 2025 IT-540 Instructions (checked 2026-10-12); 2025 Schedule D (Form 1040), Capital Gains and Losses (checked 2026-10-12)
  34. Each spouse's own Social Security joint returns On a joint return, each spouse's own Social Security is the spouse's share of the benefits by spouse.socialSecurityGross when the caller gives it (Tier 1 railroad benefits left out), else half each. It is what the per-spouse rules read: Colorado's per-spouse subtraction, Rhode Island's per-spouse modification, and the Maine, Maryland and other retirement caps reduced by the benefits each spouse received (with each spouse's own railroad benefits where the state counts them).
    Louisiana's values · engine step (compute_state_tax_detail). Sources (Social Security): 2025 Louisiana Resident Income Tax Return Instructions (IT-540) (checked 2026-10-12)
  35. Refundable state credits The credits paid beyond the tax (reported in refundableCredits; netTax = totalTax less them): earned income credits as a share of the federal EIC with each state's own age band (OK on the 2020 federal credit, DC's own childless schedule, the CalEITC table, MN's Working Family Credit), the NYC EIC and school tax credits, and the property-tax, renter, grocery and senior credits of MA, MI, NJ, ID, HI, NM, OK, AZ, NY, RI, WV, ME, DC, MN, MO, WI, IN and MT, each on its own income measure. Engine 1.13.1: a part-year NYC resident's school tax credits (the Table 2 proration chart and the rate-reduction amount on IT-360.1 line 47; IT-203 lines 60 / 60a for a part-year state resident).
    Louisiana's values · engine step (state_tax_refundable_credits). Sources (Deductions, exemptions and credits): Revenue Information Bulletin 26-019: Inflation Adjustment to Standard Deduction and Retirement Income Exemption (checked 2026-10-12); Revenue Information Bulletin 25-012: Louisiana Individual Income Tax Reform (checked 2026-10-12); 2025 IT-540 instructions (checked 2026-10-12); 2025 IT-540 instructions (line 13) (checked 2026-10-12); Rev. Proc. 2025-32 (2026 inflation adjustments) (checked 2026-10-12)

Rate schedule

A flat 3% on state taxable income.

Deductions, exemptions and credits

  • Standard deduction (or the exemption the engine carries in its place): $12,838 single, $25,676 married filing jointly, $25,676 head of household.

Social Security

Social Security benefits are fully exempt: none of the federally taxable amount enters the state base.

API value: socialSecurityRule: "exempt". The engine's input is the federally taxable amount; income tests use the sum of the income components as the adjusted-gross-income proxy.

IRA, 401(k) and private pensions

  • Pension, annuity and IRA/401(k) distributions: up to $12,324 excluded per taxpayer ($24,648 on a joint return) at age 65 or older.
  • Joint returns: the cap is per taxpayer. With the spouse's age given (couples), each spouse's own dollars are tested against that spouse's own age and cap; without it one household age applies and the $24,648 joint cap covers pooled income.

Source review notes (what the sources do not state outright, or what the engine does not carry):

Public pensions

Public (government) pension dollars, entered as pensionPublic, are exempt with no dollar cap. They do not use up the capped exclusion that other retirement income may claim.

Military retirement pay

  • Military retirement pay is fully exempt, at any age.
  • Rules are applied per taxpayer at that person's own age when the spouse's age is given. API value: rules.militaryRetirement.treatment: "exempt".

Roth conversions

A conversion draws the retirement-income exclusion together with distributions from age 65; the part above the cap is taxed as ordinary income.

Source review notes (what the sources do not state outright, or what the engine does not carry):

Capital gains

  • Net long-term gain is taxed as ordinary income.
  • Short-term gains are ordinary income.

Blindness and disability

  • The API applies these through its blind, disabled, spouse.blind and spouse.disabled fields; absent means false.

Part-year and nonresident returns

  • Part-year resident (IT-540B): the tax on the state's own income, nothing prorated.
  • Nonresident (IT-540B): the tax on the state's own income, nothing prorated.
  • The full standard deduction; the ratio prorates only federal itemized deductions in excess of it (not an input).
  • A nonresident's retirement income is not taxable by the state (4 U.S.C. §114); the API refuses it in residency.stateIncome. The credit for tax paid to another state and the earned income credits on these returns are not computed.

Married couples whose residency differs (engine 1.13.0)

With residency.spouse on a joint request, each allowed treatment is calculated and reported in residency.couple; tax is the required one, else the state's default, else the couple's residency.election, else the joint return the request's mfj names. Each rule is quoted from the state's instructions (engine 1.14.0: and its statutes, regulations, bulletins and other official guidance) in the sources below.

SpousesLouisiana's rule
One spouse a full-year resident, the other a part-year residentthe couple's choice: a joint part-year / nonresident return or a joint resident return (both taxed as full-year residents).
One spouse a full-year resident, the other a nonresidentthe couple's choice: a joint part-year / nonresident return or a joint resident return (both taxed as full-year residents).
One spouse a part-year resident, the other a nonresidentthe couple's choice: a joint part-year / nonresident return or a joint resident return (both taxed as full-year residents).
Both part-year residents, different resident periodsthe couple's choice: a joint part-year / nonresident return or a joint resident return (both taxed as full-year residents).
Both nonresidents, only one with income from the statethe couple's choice: a joint part-year / nonresident return or a joint resident return (both taxed as full-year residents).

Worked examples

Computed by the engine for the fixed households below (the same ones for every state, so states compare directly). Federal tax is not supplied, so a federal-tax deduction is not taken; the income tests use the sum of the components as income.

Household (engine inputs)State tax
Single, 67: $30,000 private pension, $20,000 IRA, $10,000 interest, $24,000 Social Security ($17,000 federally taxable), $5,000 long-term gain$1,195.14
Married filing jointly, 70: $40,000 public pension, $40,000 IRA, $20,000 interest, $40,000 Social Security ($34,000 federally taxable), $10,000 long-term gain$590.28
Single, 60: $60,000 other ordinary income and a $50,000 Roth conversion$2,914.86
Married filing jointly, 66: $30,000 IRA, a $40,000 Roth conversion, $30,000 Social Security ($25,500 federally taxable)$590.28
Single, 58: $36,000 military retirement pay and $30,000 wages$514.86
Married filing jointly, ages 67 and 61: $50,000 IRA, $10,000 interest, $30,000 Social Security ($25,500 federally taxable), each spouse's age given$660

Line by line

The intermediate lines the engine records while it computes each example (its detail record, printed as it comes out; lines that are zero are left out). The engine's documentation build checks that the lines add up to the taxable income and the tax, for every state, filing status and a grid of households. Each line links the engine step that produces it.

Single, 67: $30,000 private pension, $20,000 IRA, $10,000 interest, $24,000 Social Security ($17,000 federally taxable), $5,000 long-term gain: $1,195.14
LineAmount
Income total used by the income tests$82,000
Retirement income and conversions excluded (not in the base)$12,324
+ Other ordinary income in the base$10,000
+ Retirement income in the base$37,676
+ Long-term gain in the base$5,000
− Standard deduction$12,838
= State taxable income$39,838
Tax from the rate schedule$1,195.14
= Tax before credits$1,195.14
= Tax$1,195.14
Married filing jointly, 70: $40,000 public pension, $40,000 IRA, $20,000 interest, $40,000 Social Security ($34,000 federally taxable), $10,000 long-term gain: $590.28
LineAmount
Income total used by the income tests$144,000
Retirement income and conversions excluded (not in the base)$64,648
+ Other ordinary income in the base$20,000
+ Retirement income in the base$15,352
+ Long-term gain in the base$10,000
− Standard deduction$25,676
= State taxable income$19,676
Tax from the rate schedule$590.28
= Tax before credits$590.28
= Tax$590.28
Single, 60: $60,000 other ordinary income and a $50,000 Roth conversion: $2,914.86
LineAmount
Income total used by the income tests$110,000
+ Other ordinary income in the base$60,000
+ Roth conversion in the base$50,000
− Standard deduction$12,838
= State taxable income$97,162
Tax from the rate schedule$2,914.86
= Tax before credits$2,914.86
= Tax$2,914.86
Married filing jointly, 66: $30,000 IRA, a $40,000 Roth conversion, $30,000 Social Security ($25,500 federally taxable): $590.28
LineAmount
Income total used by the income tests$95,500
Retirement income and conversions excluded (not in the base)$24,648
+ Retirement income in the base$45,352
− Standard deduction$25,676
= State taxable income$19,676
Tax from the rate schedule$590.28
= Tax before credits$590.28
= Tax$590.28
Single, 58: $36,000 military retirement pay and $30,000 wages: $514.86
LineAmount
Income total used by the income tests$66,000
Military pay excluded (not in the base)$36,000
+ Other ordinary income in the base$30,000
− Standard deduction$12,838
= State taxable income$17,162
Tax from the rate schedule$514.86
= Tax before credits$514.86
= Tax$514.86
Married filing jointly, ages 67 and 61: $50,000 IRA, $10,000 interest, $30,000 Social Security ($25,500 federally taxable), each spouse's age given: $660
LineAmount
Income total used by the income tests$85,500
Retirement income and conversions excluded (not in the base)$12,324
+ Other ordinary income in the base$10,000
+ Retirement income in the base$37,676
− Standard deduction$25,676
= State taxable income$22,000
Tax from the rate schedule$660
= Tax before credits$660
= Tax$660

After 2026: how the amounts move

A request with projection (API) estimates a later tax year from these rules: every dollar amount and age test below moves the way Louisiana's law moves it. Rates and the rules themselves stay the 2026 ones (how projection works).

Amounts (engine fields)After 2026What the law says, and the source
std_deduction_single, std_deduction_mfj, std_deduction_hohIndexed: CPI-U (BLS); prior-year amount times the CPI-U percentage increase (R.S. 47:294, per LDR RIB 26-019); the increase rounded to the nearest $1.Act 11 (2024 3rd Ex. Sess.) set the standard deduction at $12,500 single/MFS and $25,000 joint/HOH/surviving spouse for 2025, adjusted every year from January 1, 2026 by the CPI-U: each year the prior year's amounts times the CPI-U percentage increase (R.S. 47:294, as LDR's RIB 26-019 states it). The official 2026 amounts are $12,838 and $25,676 (12,500 x 1.027 = 12,837.50, shown as $12,838: to the nearest dollar), which the engine carries.
retirement_income_exclusion_single, retirement_income_exclusion_mfjIndexed: CPI-U (BLS); prior-year amount times the CPI-U percentage increase (R.S. 47:44.1, per LDR RIB 26-019); the increase rounded to the nearest $1.Act 11 raised the retirement income exemption for individuals 65 or older to $12,000 per person for 2025 and adjusts it every year from January 1, 2026 by the CPI-U (R.S. 47:44.1, as LDR's RIB 26-019 states it): $12,324 for 2026 (12,000 x 1.027), which the engine carries; LDR's figures are whole dollars.
retirement_exclusion_min_age, conversion_exclusion_min_ageAttained age: the same age in every year.The retirement income exemption is for individuals age 65 or older: a fixed attained age.
dis_income_capFixed in law: held at the rules-year amount in every later year.The $6,000 disability income exclusion of R.S. 47:44.1(B) is fixed in law: Act 11 of the 2024 Third Extraordinary Session amended only R.S. 47:44.1(A) and its inflation clause covers 'the exemption provided for in this Subsection' (A, the retirement income exemption); LDR's RIB 26-019 adjusts only the standard deduction and the retirement income exemption for 2026. Engine 1.12.0 (settled from the session law; was unknown).
nofile_threshold_single, nofile_threshold_mfj, nofile_threshold_hohTied to an indexed federal amount: the federal basic standard deduction, IRC 63(c)(2)/63(c)(7) (chained CPI-U); the increase rounded down to a multiple of $50.These are the federal basic standard deduction amounts (IRC 63(c)(2); 2026 $16,100 single/MFS, $24,150 HOH, $32,200 joint), indexed from 2026 by the chained CPI with increases rounded down to $50 (IRC 63(c)(7)(B)(ii)). Louisiana's no-tax rule applies to residents not required to file a federal return, whose gross-income filing thresholds equal the federal standard deduction (plus the additional amounts for age).
  • 2025 IT-540 Resident Income Tax Instructions (revised) (Louisiana Department of Revenue, instructions): Filing tied to the federal filing requirement. Quoted: "If you are a Louisiana resident who is required to file a federal individual". Checked 2026-10-12.
  • 26 U.S.C. 63 (taxable income defined) (Cornell LII (U.S. Code), federal): Federal standard deduction indexing and rounding. Quoted: "the $23,625 and $15,750 amounts in subparagraph (A) shall each be increased by an amount equal to"; "such increase shall be rounded to the next lowest multiple of $50.". Checked 2026-10-12.
  • Rev. Proc. 2025-32 (2026 inflation adjustments) (Internal Revenue Service, federal): 2026 federal standard deduction amounts. Quoted: "For taxable years beginning in 2026, the standard deduction amounts under § 63(c)(2) are as follows:". Checked 2026-10-12.
nofile_aged_add_unmarried, nofile_aged_add_marriedTied to an indexed federal amount: the federal additional standard deduction for age/blindness, IRC 63(f), indexed under IRC 63(c)(4) (chained CPI-U); the increase rounded down to a multiple of $50.These are the federal additional standard deduction amounts for age 65+/blindness (IRC 63(f); 2026 $1,650 married, $2,050 unmarried), indexed under IRC 63(c)(4) by the chained CPI, increases rounded down to $50 (IRC 1(f)(7)(A)).
  • 26 U.S.C. 63 (taxable income defined) (Cornell LII (U.S. Code), federal): 63(c)(4) indexes the subsection (f) amounts. Quoted: "each dollar amount contained in paragraph (2)(B), (2)(C), or (5) or subsection (f) shall be increased by an amount equal to". Checked 2026-10-12.
  • 26 U.S.C. 1 (tax imposed) (Cornell LII (U.S. Code), federal): 1(f)(7)(A) rounds a 63(c)(4) increase down to $50. Quoted: "If any increase determined under paragraph (2)(A), section 63(c)(4), section 68(b)(2)". Checked 2026-10-12.
  • Rev. Proc. 2025-32 (2026 inflation adjustments) (Internal Revenue Service, federal): 2026 amounts. Quoted: "deduction amount under § 63(f) for the aged or the blind is $1,650". Checked 2026-10-12.
nofile_threshold_mfsFixed in law: held at the rules-year amount in every later year.The federal filing threshold on a married-filing-separately return is $5 at any age, a fixed amount.
  • Publication 501 (Internal Revenue Service, federal): MFS threshold $5. Quoted: "married filing separately any age $5". Checked 2026-10-12.
cap_loss_limit, cap_loss_limit_mfsFixed in law: held at the rules-year amount in every later year.The state follows the federal net capital loss limit of IRC 1211(b): $3,000 ($1,500 MFS), a fixed amount with no inflation adjustment.
  • 26 U.S.C. 1211 (limitation on capital losses) (Cornell LII (U.S. Code), federal): The capital-loss deduction against ordinary income is a fixed $3,000 ($1,500 MFS); section 1211 contains no inflation adjustment. Quoted: "$3,000 ($1,500 in the case of a married individual filing a separate return), or". Checked 2026-10-12.

Enacted for later years, not applied by the projection

None found: the research found no change enacted for years after 2026 beyond the schedules above.

What the engine does not calculate, and known approximations

What the engine does not calculate for any state (itemized deductions, credits beyond those listed, part-year residents, and more) is listed on the calculation order page.

Verification

Worksheet-tested Golden rows follow the IT-540 instructions' Schedule E code 06E definition of retirement income, including per-spouse rows.