State tax docs / States / Missouri

Missouri state income tax: engine rules, 2026

How the QuantCalc engine computes Missouri 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 · Interaction with the federal return · 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 MO).

How the tax is computed

Every step the engine takes for Missouri, 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 Missouri'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):

	Single	Married filing jointly	Married filing separately	Head of household
Rate schedule used	single schedule	joint schedule	single schedule	single schedule
Top rate	4.7% from $9,436	4.7% from $9,436	4.7% from $9,436	4.7% from $9,436
Standard deduction, under 65	$16,100	$32,200	$16,100	$24,150
Standard deduction at 70 (joint: both 70)	$18,150	$35,500	$17,750	$26,200
Personal exemption	none	none	none	$1,400
Age subtractions at 70 (joint: both 70)	none	none	none	none

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.
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.
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.
Missouri's values · engine step (select_brackets). Sources (Rate schedule): 2026 Missouri Withholding Tax Formula (checked 2026-10-12); RSMo 143.011 Resident individuals - tax rates (checked 2026-10-12); 2025 Form MO-1040 Instructions (lines 7, 27, 30) (checked 2026-10-12)
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).
Missouri's values · engine step (select_brackets). Sources (Rate schedule): 2026 Missouri Withholding Tax Formula (checked 2026-10-12); RSMo 143.011 Resident individuals - tax rates (checked 2026-10-12); 2025 Form MO-1040 Instructions (lines 7, 27, 30) (checked 2026-10-12)
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.
Missouri's values · engine step (select_brackets). Sources (Rate schedule): 2026 Missouri Withholding Tax Formula (checked 2026-10-12); RSMo 143.011 Resident individuals - tax rates (checked 2026-10-12); 2025 Form MO-1040 Instructions (lines 7, 27, 30) (checked 2026-10-12)
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.
Short-term gains exempt Short-term gain (a part of other ordinary income) leaves the base; it stays in the income total above.
Missouri's values · engine step (compute_state_tax_detail). Sources (Capital gains): RSMo 143.121 Missouri adjusted gross income (checked 2026-10-12); 2025 Individual Income Tax Year Changes (checked 2026-10-12); 2025 Form MO-1040 Instructions (archived) (checked 2026-10-12); 2025 Schedule D (Form 1040), Capital Gains and Losses (checked 2026-10-12)
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.
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.
Income tests on the state AGI Where the state's retirement income test and federal-tax percentage read its own AGI, the income total is federal AGI less the state subtractions the inputs carry: the military pay excluded and every capital gain (long- and short-term).
Missouri's values · engine step (compute_state_tax_detail). Sources (IRA, 401(k) and private pensions): RSMo 143.124 Public and private pensions exemption (checked 2026-10-12); 2025 Form MO-A Individual Income Tax Adjustments (checked 2026-10-12); Pension FAQs (checked 2026-10-12); 2025 Form MO-A (Part 3 Section B) (checked 2026-09-27); 2025 Form MO-1040 Instructions (MO-A Part 1 lines 10 and 18) (checked 2026-10-12)
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.
Missouri's values · engine step (compute_state_tax_detail). Sources (Military retirement pay): MO 1040 Instructions 2025 (checked 2026-10-12); Military Reference Guide (checked 2026-10-12)
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.
Missouri's values · engine step (military_exempt_one). Sources (Military retirement pay): MO 1040 Instructions 2025 (checked 2026-10-12); Military Reference Guide (checked 2026-10-12)
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).
Missouri's values · engine step (compute_state_tax_detail). Sources (Capital gains): RSMo 143.121 Missouri adjusted gross income (checked 2026-10-12); 2025 Individual Income Tax Year Changes (checked 2026-10-12); 2025 Form MO-1040 Instructions (archived) (checked 2026-10-12); 2025 Schedule D (Form 1040), Capital Gains and Losses (checked 2026-10-12)
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.
Missouri's values · engine step (compute_state_tax_detail). Sources (Public pensions): RSMo 143.124 Public and private pensions exemption (checked 2026-10-12); Pension FAQs (checked 2026-10-12); RSMo 143.124 (checked 2026-10-12)
Public pension exemption reduced by the Social Security exemption The capped public-pension exemption is reduced by the Social Security the state exempts (Tier 1 railroad benefits left out): from age 50, and under that age where the benefits are exempt as disability benefits (said to be, or not said where the state reads the fact for the household — see the disability-age rule). On the per-person path each spouse's own share (by spouse.socialSecurityGross, else half each); on a joint return with a spouse object but no ages, the spouse's own share when only the primary's benefits are said not to be disability benefits.
Missouri's values · engine step (compute_state_tax_detail). Sources (Public pensions): RSMo 143.124 Public and private pensions exemption (checked 2026-10-12); Pension FAQs (checked 2026-10-12); RSMo 143.124 (checked 2026-10-12)
Social Security below the exemption age 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) Where Social Security is exempt only from an age unless it is disability benefits, a person under that age whom the caller says does not receive disability benefits keeps their share of the taxable benefits in the base (the share by the spouse's stated gross benefits, else half). Not said: the benefits stay exempt, the earlier result. Disability benefits, and benefits under that age not said to be other benefits (which stay exempt), also reduce the public-pension exemption at any age where the state says so.
Missouri's values · engine step (compute_state_tax_detail). Sources (Social Security): RSMo 143.125 Social Security benefits and disability benefits exemption (checked 2026-10-12); Pension FAQs (checked 2026-10-12); Missouri Department of Revenue: MO-A_2025.pdf (checked 2026-10-12); Missouri Department of Revenue: MO-1040 Instructions_2025.pdf (checked 2026-10-12); Missouri Revisor of Statutes: section 143.124 (checked 2026-10-12); RSMo 143.125 (Social Security exemption) (checked 2026-10-12); RSMo 143.124 (public pension exemption) (checked 2026-10-12)
Social Security disability: not said, and the household fact 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) Benefits of a person under the age whose disability status is not said are exempt as disability benefits everywhere — they also reduce that person's public-pension exemption. Without a spouse object the top-level socialSecurityDisability describes both halves of the household's benefits.
Missouri's values · engine step (compute_state_tax_detail). Sources (Social Security): RSMo 143.125 Social Security benefits and disability benefits exemption (checked 2026-10-12); Pension FAQs (checked 2026-10-12); Missouri Department of Revenue: MO-A_2025.pdf (checked 2026-10-12); Missouri Department of Revenue: MO-1040 Instructions_2025.pdf (checked 2026-10-12); Missouri Revisor of Statutes: section 143.124 (checked 2026-10-12); RSMo 143.125 (Social Security exemption) (checked 2026-10-12); RSMo 143.124 (public pension exemption) (checked 2026-10-12)
Social Security exempt None of the federally taxable benefit enters the base.
Missouri's values · engine step (ss_amount_in_state_base). Sources (Social Security): RSMo 143.125 Social Security benefits and disability benefits exemption (checked 2026-10-12); Pension FAQs (checked 2026-10-12); Missouri Department of Revenue: MO-A_2025.pdf (checked 2026-10-12); Missouri Department of Revenue: MO-1040 Instructions_2025.pdf (checked 2026-10-12); Missouri Revisor of Statutes: section 143.124 (checked 2026-10-12); RSMo 143.125 (Social Security exemption) (checked 2026-10-12); RSMo 143.124 (public pension exemption) (checked 2026-10-12)
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.
Missouri's values · engine step (compute_state_tax_detail). Sources (IRA, 401(k) and private pensions): RSMo 143.124 Public and private pensions exemption (checked 2026-10-12); 2025 Form MO-A Individual Income Tax Adjustments (checked 2026-10-12); Pension FAQs (checked 2026-10-12); 2025 Form MO-A (Part 3 Section B) (checked 2026-09-27); 2025 Form MO-1040 Instructions (MO-A Part 1 lines 10 and 18) (checked 2026-10-12)
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.
Missouri's values · engine step (compute_state_tax_detail). Sources (IRA, 401(k) and private pensions): RSMo 143.124 Public and private pensions exemption (checked 2026-10-12); 2025 Form MO-A Individual Income Tax Adjustments (checked 2026-10-12); Pension FAQs (checked 2026-10-12); 2025 Form MO-A (Part 3 Section B) (checked 2026-09-27); 2025 Form MO-1040 Instructions (MO-A Part 1 lines 10 and 18) (checked 2026-10-12)
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.
Missouri's values · engine step (compute_state_tax_detail). Sources (IRA, 401(k) and private pensions): RSMo 143.124 Public and private pensions exemption (checked 2026-10-12); 2025 Form MO-A Individual Income Tax Adjustments (checked 2026-10-12); Pension FAQs (checked 2026-10-12); 2025 Form MO-A (Part 3 Section B) (checked 2026-09-27); 2025 Form MO-1040 Instructions (MO-A Part 1 lines 10 and 18) (checked 2026-10-12)
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.
Missouri's values · engine step (compute_state_tax_detail). Sources (Roth conversions): RSMo 143.121 Missouri adjusted gross income (checked 2026-10-12); RSMo 143.124 Public and private pensions exemption (checked 2026-10-12)
Income limit on the exclusion When the income total (Social Security left out where the state says so) exceeds the limit, the exclusion is lost (a cliff), reduced dollar for dollar after the cap (subtractive), or phased out in proportion over the range. Head-of-household and separate returns use their own limits where the state sets them.
Missouri's values · engine step (retirement_distributions_in_state_base). Sources (IRA, 401(k) and private pensions): RSMo 143.124 Public and private pensions exemption (checked 2026-10-12); 2025 Form MO-A Individual Income Tax Adjustments (checked 2026-10-12); Pension FAQs (checked 2026-10-12); 2025 Form MO-A (Part 3 Section B) (checked 2026-09-27); 2025 Form MO-1040 Instructions (MO-A Part 1 lines 10 and 18) (checked 2026-10-12)
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.
Missouri's values · engine step (retirement_distributions_in_state_base). Sources (IRA, 401(k) and private pensions): RSMo 143.124 Public and private pensions exemption (checked 2026-10-12); 2025 Form MO-A Individual Income Tax Adjustments (checked 2026-10-12); Pension FAQs (checked 2026-10-12); 2025 Form MO-A (Part 3 Section B) (checked 2026-09-27); 2025 Form MO-1040 Instructions (MO-A Part 1 lines 10 and 18) (checked 2026-10-12)
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.
Missouri's values · engine step (retirement_distributions_in_state_base). Sources (IRA, 401(k) and private pensions): RSMo 143.124 Public and private pensions exemption (checked 2026-10-12); 2025 Form MO-A Individual Income Tax Adjustments (checked 2026-10-12); Pension FAQs (checked 2026-10-12); 2025 Form MO-A (Part 3 Section B) (checked 2026-09-27); 2025 Form MO-1040 Instructions (MO-A Part 1 lines 10 and 18) (checked 2026-10-12)
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.
Missouri's values · engine step (per_taxpayer_cap_single). Sources (IRA, 401(k) and private pensions): RSMo 143.124 Public and private pensions exemption (checked 2026-10-12); 2025 Form MO-A Individual Income Tax Adjustments (checked 2026-10-12); Pension FAQs (checked 2026-10-12); 2025 Form MO-A (Part 3 Section B) (checked 2026-09-27); 2025 Form MO-1040 Instructions (MO-A Part 1 lines 10 and 18) (checked 2026-10-12)
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.
Missouri's values · engine step (compute_state_tax_detail). Sources (Capital gains): RSMo 143.121 Missouri adjusted gross income (checked 2026-10-12); 2025 Individual Income Tax Year Changes (checked 2026-10-12); 2025 Form MO-1040 Instructions (archived) (checked 2026-10-12); 2025 Schedule D (Form 1040), Capital Gains and Losses (checked 2026-10-12)
Additional standard deduction at 65 The unmarried amount for a single or head-of-household filer 65 or older, the married amount for each spouse 65 or older, added to the standard deduction before any phase-out.
Missouri's values · engine step (compute_state_tax_detail). Sources (Deductions, exemptions and credits): RSMo 143.131 Missouri standard deduction, when used, amount (checked 2026-10-12); 2026 Missouri Withholding Tax Formula (checked 2026-10-12); 2025 Form MO-1040 Instructions (checked 2026-10-12); Rev. Proc. 2025-32 (2026 inflation adjustments) (checked 2026-10-12); RSMo 143.161 (additional exemptions) (checked 2026-10-12); 2025 Form MO-1040 Instructions (line 15) (checked 2026-10-12); 2025 Form MO-PTS Property Tax Credit Schedule (checked 2026-10-01); RSMo 135.030 Formula for determining credits (effective 28 Aug 2025, A.L. 2025 H.B. 594 & 508) (checked 2026-10-12); RSMo 135.010 Definitions (effective 28 Aug 2025) (checked 2026-10-12); RSMo 135.025 Accrued taxes and rent constituting taxes to be totaled (effective 28 Aug 2025) (checked 2026-10-12); RSMo 135.020 Credits, how applied, considered overpayment (checked 2026-10-12); SS#2 for HCS for HB 594 & 508 (2025), Truly Agreed To and Finally Passed (1683S.04T) (checked 2026-10-12)
Additional standard deduction for blindness only when the caller says a person is blind or disabled The unmarried amount for a blind single or head-of-household filer, the married amount for each blind spouse, added to the standard deduction before any phase-out. Age and blindness are separate boxes, so a person 65 or older and blind gets both.
Missouri's values · engine step (compute_state_tax_detail). Sources (Blindness and disability): 2025 MO-1040 instructions (archived copy) (checked 2026-10-12); Rev. Proc. 2025-32 (2026 inflation adjustments) (checked 2026-10-12)
Head-of-household additional exemption head of household A head of household adds the state's additional exemption to the personal exemption.
Missouri's values · engine step (compute_state_tax_detail). Sources (Deductions, exemptions and credits): RSMo 143.131 Missouri standard deduction, when used, amount (checked 2026-10-12); 2026 Missouri Withholding Tax Formula (checked 2026-10-12); 2025 Form MO-1040 Instructions (checked 2026-10-12); Rev. Proc. 2025-32 (2026 inflation adjustments) (checked 2026-10-12); RSMo 143.161 (additional exemptions) (checked 2026-10-12); 2025 Form MO-1040 Instructions (line 15) (checked 2026-10-12); 2025 Form MO-PTS Property Tax Credit Schedule (checked 2026-10-01); RSMo 135.030 Formula for determining credits (effective 28 Aug 2025, A.L. 2025 H.B. 594 & 508) (checked 2026-10-12); RSMo 135.010 Definitions (effective 28 Aug 2025) (checked 2026-10-12); RSMo 135.025 Accrued taxes and rent constituting taxes to be totaled (effective 28 Aug 2025) (checked 2026-10-12); RSMo 135.020 Credits, how applied, considered overpayment (checked 2026-10-12); SS#2 for HCS for HB 594 & 508 (2025), Truly Agreed To and Finally Passed (1683S.04T) (checked 2026-10-12)
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.
Federal income tax deduction by percentage band only when the caller supplies federal tax Only when the caller supplies federal tax: the percentage of the federal tax for the band that holds the state AGI (inclusive tops; none above the last band), at most the cap (the joint cap on a joint return).
Missouri's values · engine step (compute_state_tax_detail). Sources (Interaction with the federal return): RSMo 143.171 (federal income tax deduction) (checked 2026-10-12); 2025 Form MO-1040 Instructions (lines 9-13) (checked 2026-10-12)
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.
Separate-return scaling married filing separately For the halved-joint rule, taxable income is doubled before the schedule and the result halved.
Missouri's values · engine step (compute_state_tax_detail). Sources (Rate schedule): 2026 Missouri Withholding Tax Formula (checked 2026-10-12); RSMo 143.011 Resident individuals - tax rates (checked 2026-10-12); 2025 Form MO-1040 Instructions (lines 7, 27, 30) (checked 2026-10-12)
A separate tax for each spouse joint returns with each spouse's own amounts given On a joint return with each spouse's own amounts, each spouse is taxed on the schedule on their share of taxable income, the share being their state AGI over the couple's (a spouse with negative income: none): own wages, own distributions less own military pay, own conversion, own share of the taxable Social Security (by the gross split, else half) and half the other ordinary income; gains are subtracted. The form rounds the share to a whole percent; the engine uses the exact share. Without the spouse's amounts the schedule applies once.
Missouri's values · engine step (compute_state_tax_detail). Sources (Rate schedule): 2026 Missouri Withholding Tax Formula (checked 2026-10-12); RSMo 143.011 Resident individuals - tax rates (checked 2026-10-12); 2025 Form MO-1040 Instructions (lines 7, 27, 30) (checked 2026-10-12)
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.
Missouri's values · engine step (apply_state_brackets). Sources (Rate schedule): 2026 Missouri Withholding Tax Formula (checked 2026-10-12); RSMo 143.011 Resident individuals - tax rates (checked 2026-10-12); 2025 Form MO-1040 Instructions (lines 7, 27, 30) (checked 2026-10-12)
The federal earned income credit The federal earned income credit the state credits read: the credit rate on earned income up to the maximum, less the phase-out rate on the larger of the income total and earned income over the start (joint start on a joint return) — where the state says so, measured from the income at which the maximum is reached when that is higher; none above the investment-income limit; by qualifying children (dependents under 19, students under 24, disabled at any age; at most 3); without one the filer or a spouse must be at least the minimum age where the state sets one and under the maximum age. Not on a separate return.
Missouri's values · engine step (federal_eic). Sources (Deductions, exemptions and credits): RSMo 143.131 Missouri standard deduction, when used, amount (checked 2026-10-12); 2026 Missouri Withholding Tax Formula (checked 2026-10-12); 2025 Form MO-1040 Instructions (checked 2026-10-12); Rev. Proc. 2025-32 (2026 inflation adjustments) (checked 2026-10-12); RSMo 143.161 (additional exemptions) (checked 2026-10-12); 2025 Form MO-1040 Instructions (line 15) (checked 2026-10-12); 2025 Form MO-PTS Property Tax Credit Schedule (checked 2026-10-01); RSMo 135.030 Formula for determining credits (effective 28 Aug 2025, A.L. 2025 H.B. 594 & 508) (checked 2026-10-12); RSMo 135.010 Definitions (effective 28 Aug 2025) (checked 2026-10-12); RSMo 135.025 Accrued taxes and rent constituting taxes to be totaled (effective 28 Aug 2025) (checked 2026-10-12); RSMo 135.020 Credits, how applied, considered overpayment (checked 2026-10-12); SS#2 for HCS for HB 594 & 508 (2025), Truly Agreed To and Finally Passed (1683S.04T) (checked 2026-10-12)
State earned income credit as a share of the federal credit Where the state's credit is simply a share of the federal earned income credit (the step above), that share, nonrefundable, after the other credits the form takes first.
Missouri's values · engine step (compute_state_tax_detail). Sources (Deductions, exemptions and credits): RSMo 143.131 Missouri standard deduction, when used, amount (checked 2026-10-12); 2026 Missouri Withholding Tax Formula (checked 2026-10-12); 2025 Form MO-1040 Instructions (checked 2026-10-12); Rev. Proc. 2025-32 (2026 inflation adjustments) (checked 2026-10-12); RSMo 143.161 (additional exemptions) (checked 2026-10-12); 2025 Form MO-1040 Instructions (line 15) (checked 2026-10-12); 2025 Form MO-PTS Property Tax Credit Schedule (checked 2026-10-01); RSMo 135.030 Formula for determining credits (effective 28 Aug 2025, A.L. 2025 H.B. 594 & 508) (checked 2026-10-12); RSMo 135.010 Definitions (effective 28 Aug 2025) (checked 2026-10-12); RSMo 135.025 Accrued taxes and rent constituting taxes to be totaled (effective 28 Aug 2025) (checked 2026-10-12); RSMo 135.020 Credits, how applied, considered overpayment (checked 2026-10-12); SS#2 for HCS for HB 594 & 508 (2025), Truly Agreed To and Finally Passed (1683S.04T) (checked 2026-10-12)
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.
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).
Missouri's values · engine step (state_tax_effective_config). Sources (Rate schedule): 2026 Missouri Withholding Tax Formula (checked 2026-10-12); RSMo 143.011 Resident individuals - tax rates (checked 2026-10-12); 2025 Form MO-1040 Instructions (lines 7, 27, 30) (checked 2026-10-12)
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.
Missouri's values · engine step (compute_state_tax_detail). Sources (Social Security): RSMo 143.125 Social Security benefits and disability benefits exemption (checked 2026-10-12); Pension FAQs (checked 2026-10-12); Missouri Department of Revenue: MO-A_2025.pdf (checked 2026-10-12); Missouri Department of Revenue: MO-1040 Instructions_2025.pdf (checked 2026-10-12); Missouri Revisor of Statutes: section 143.124 (checked 2026-10-12); RSMo 143.125 (Social Security exemption) (checked 2026-10-12); RSMo 143.124 (public pension exemption) (checked 2026-10-12)
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.
Missouri's values · engine step (compute_state_tax_detail). Sources (Capital gains): RSMo 143.121 Missouri adjusted gross income (checked 2026-10-12); 2025 Individual Income Tax Year Changes (checked 2026-10-12); 2025 Form MO-1040 Instructions (archived) (checked 2026-10-12); 2025 Schedule D (Form 1040), Capital Gains and Losses (checked 2026-10-12)
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).
Missouri's values · engine step (compute_state_tax_detail). Sources (Social Security): RSMo 143.125 Social Security benefits and disability benefits exemption (checked 2026-10-12); Pension FAQs (checked 2026-10-12); Missouri Department of Revenue: MO-A_2025.pdf (checked 2026-10-12); Missouri Department of Revenue: MO-1040 Instructions_2025.pdf (checked 2026-10-12); Missouri Revisor of Statutes: section 143.124 (checked 2026-10-12); RSMo 143.125 (Social Security exemption) (checked 2026-10-12); RSMo 143.124 (public pension exemption) (checked 2026-10-12)
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).
Missouri's values · engine step (state_tax_refundable_credits). Sources (Deductions, exemptions and credits): RSMo 143.131 Missouri standard deduction, when used, amount (checked 2026-10-12); 2026 Missouri Withholding Tax Formula (checked 2026-10-12); 2025 Form MO-1040 Instructions (checked 2026-10-12); Rev. Proc. 2025-32 (2026 inflation adjustments) (checked 2026-10-12); RSMo 143.161 (additional exemptions) (checked 2026-10-12); 2025 Form MO-1040 Instructions (line 15) (checked 2026-10-12); 2025 Form MO-PTS Property Tax Credit Schedule (checked 2026-10-01); RSMo 135.030 Formula for determining credits (effective 28 Aug 2025, A.L. 2025 H.B. 594 & 508) (checked 2026-10-12); RSMo 135.010 Definitions (effective 28 Aug 2025) (checked 2026-10-12); RSMo 135.025 Accrued taxes and rent constituting taxes to be totaled (effective 28 Aug 2025) (checked 2026-10-12); RSMo 135.020 Credits, how applied, considered overpayment (checked 2026-10-12); SS#2 for HCS for HB 594 & 508 (2025), Truly Agreed To and Finally Passed (1683S.04T) (checked 2026-10-12)

Rate schedule

Single

Taxable income from	to	Rate
$0	$1,348	0%
$1,348	$2,696	2%
$2,696	$4,044	2.5%
$4,044	$5,392	3%
$5,392	$6,740	3.5%
$6,740	$8,088	4%
$8,088	$9,436	4.5%
$9,436	and up	4.7%

Married filing jointly uses the same thresholds as single.

Head of household uses the single schedule.

Married filing separately: one schedule applies to every filing status, so the engine uses it unscaled with the single deduction.

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

The statute shows only the unindexed base table; the 2026 indexed edges come from the DOR withholding formula, not an individual-return rate chart (the 2026 MO-1040 tax chart is not yet published).

2026 Missouri Withholding Tax Formula, Missouri Department of Revenue. For 2026 Missouri applies eight rates from 0% to 4.7% to taxable income, with annual bracket edges at $1,348, $2,696, $4,044, $5,392, $6,740, $8,088 and $9,436, the same for every filer. Checked 2026-10-12.
RSMo 143.011 Resident individuals - tax rates, Missouri Revisor of Statutes. Missouri taxes resident individuals on one graduated table whose bracket edges are indexed annually for inflation and published by the Director of Revenue. Checked 2026-10-12.
2025 Form MO-1040 Instructions (lines 7, 27, 30), Missouri Department of Revenue (Internet Archive capture). On a combined return a separate tax is computed for each spouse on their share of taxable income, the share being their Missouri AGI over the couple's (the form rounds it to a whole percent; the engine uses the exact share) (engine 1.8.0). Checked 2026-10-12.

Deductions, exemptions and credits

Standard deduction (or the exemption the engine carries in its place): $16,100 single, $32,200 married filing jointly, $24,150 head of household.
The standard deduction includes $2,050 more for a single or head-of-household filer 65 or older, and $1,650 more for each spouse 65 or older on a married return.

RSMo 143.131 Missouri standard deduction, when used, amount, Missouri Revisor of Statutes. The Missouri standard deduction equals the allowable federal standard deduction. Checked 2026-10-12.
2026 Missouri Withholding Tax Formula, Missouri Department of Revenue. For 2026 the Missouri standard deduction is $16,100 for a single filer and $32,200 for a married couple (withholding status 'married and spouse does not work'). Checked 2026-10-12.
2025 Form MO-1040 Instructions, Missouri Department of Revenue (Internet Archive capture). Missouri line 14 adds the federal additional standard deduction for each qualifying condition (65 or older, blind): $2,000 single/head of household and $1,600 married for TY2025, the federal figures. Checked 2026-10-12.
Rev. Proc. 2025-32 (2026 inflation adjustments), Internal Revenue Service. For 2026 the federal additional standard deduction for the aged is $1,650, or $2,050 for an unmarried taxpayer — the amounts Missouri's deduction follows. Checked 2026-10-12.
RSMo 143.161 (additional exemptions), Missouri Revisor of Statutes. A head of household deducts an additional $1,400 (fixed in the statute) (engine 1.8.0). Checked 2026-10-12.
2025 Form MO-1040 Instructions (line 15), Missouri Department of Revenue (Internet Archive capture). Line 15: the $1,400 additional exemption for a head of household or qualifying widow(er). Checked 2026-10-12.
2025 Form MO-PTS Property Tax Credit Schedule, Missouri Department of Revenue. Property Tax Credit (engine 1.12.0): MO-PTS, 65 or older or disabled, the statute's formula on the 2026 amounts. Checked 2026-10-01.
RSMo 135.030 Formula for determining credits (effective 28 Aug 2025, A.L. 2025 H.B. 594 & 508), Missouri Revisor of Statutes. Property Tax Credit (engine 1.12.0): MO-PTS, 65 or older or disabled, the statute's formula on the 2026 amounts. Checked 2026-10-12.
RSMo 135.010 Definitions (effective 28 Aug 2025), Missouri Revisor of Statutes. Property Tax Credit (engine 1.12.0): MO-PTS, 65 or older or disabled, the statute's formula on the 2026 amounts. Checked 2026-10-12.
RSMo 135.025 Accrued taxes and rent constituting taxes to be totaled (effective 28 Aug 2025), Missouri Revisor of Statutes. Property Tax Credit (engine 1.12.0): MO-PTS, 65 or older or disabled, the statute's formula on the 2026 amounts. Checked 2026-10-12.
RSMo 135.020 Credits, how applied, considered overpayment, Missouri Revisor of Statutes. Property Tax Credit (engine 1.12.0): MO-PTS, 65 or older or disabled, the statute's formula on the 2026 amounts. Checked 2026-10-12.
SS#2 for HCS for HB 594 & 508 (2025), Truly Agreed To and Finally Passed (1683S.04T), Missouri House of Representatives. Property Tax Credit (engine 1.12.0): MO-PTS, 65 or older or disabled, the statute's formula on the 2026 amounts. Checked 2026-10-12.

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.

RSMo 143.125 Social Security benefits and disability benefits exemption, Missouri Revisor of Statutes. From tax year 2024 Missouri subtracts 100% of federally taxable Social Security benefits (age 62+) and Social Security disability benefits, with no income or filing-status limit. Checked 2026-10-12.
Pension FAQs, Missouri Department of Revenue. Missouri does not tax Social Security benefits of recipients age 62+ or Social Security disability benefits for tax years 2024 and later. Checked 2026-10-12.
Missouri Department of Revenue: MO-A_2025.pdf, Missouri Department of Revenue. Engine 1.7.0: Form MO-A Part 3 Section C: Social Security is exempt from 62, Social Security disability benefits at any age, and that exemption reduces the public-pension exemption (Section A line 3). Checked 2026-10-12.
Missouri Department of Revenue: MO-1040 Instructions_2025.pdf, Missouri Department of Revenue (archived copy). Engine 1.7.0: Form MO-A Part 3 Section C: Social Security is exempt from 62, Social Security disability benefits at any age, and that exemption reduces the public-pension exemption (Section A line 3). Checked 2026-10-12.
Missouri Revisor of Statutes: section 143.124, Missouri Revisor of Statutes. Engine 1.7.0: Form MO-A Part 3 Section C: Social Security is exempt from 62, Social Security disability benefits at any age, and that exemption reduces the public-pension exemption (Section A line 3). Checked 2026-10-12.
RSMo 143.125 (Social Security exemption), Missouri Revisor of Statutes. Social Security is exempt at 62 and Social Security disability benefits at any age; benefits of a person under 62 whose disability status is not said are exempt as disability benefits and reduce the public-pension exemption as well, and without a spouse object the top-level fact describes both halves (engine 1.8.0). Checked 2026-10-12.
RSMo 143.124 (public pension exemption), Missouri Revisor of Statutes. The public-pension exemption is reduced by any Social Security exemption under 143.125. Checked 2026-10-12.

IRA, 401(k) and private pensions

Pension, annuity and IRA/401(k) distributions: up to $6,000 excluded per taxpayer ($12,000 on a joint return) at any age.
When state AGI (the income total less the military pay excluded and every capital gain) less the taxable Social Security exceeds $25,000 (single) / $32,000 (MFJ), each dollar over reduces the exclusion by a dollar (after the cap is applied).
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 $12,000 joint cap covers pooled income.

RSMo 143.124 Public and private pensions exemption, Missouri Revisor of Statutes. Each taxpayer may subtract up to $6,000 of private-source pension, annuity and traditional IRA income; the exemption is reduced dollar for dollar once Missouri AGI (excluding Social Security) exceeds $25,000 single/HOH, $32,000 married filing combined or $16,000 married filing separately. Checked 2026-10-12.
2025 Form MO-A Individual Income Tax Adjustments, Missouri Department of Revenue. The private-pension worksheet caps each spouse's private pension/IRA at $6,000, tests Missouri AGI minus taxable Social Security against $25,000/$32,000/$16,000, and subtracts the excess from the summed exemption. Checked 2026-10-12.
Pension FAQs, Missouri Department of Revenue. The private pension exemption is at most $6,000 and is reduced by the amount Missouri AGI exceeds $25,000 single, $32,000 married filing combined or $16,000 married filing separately. Checked 2026-10-12.
2025 Form MO-A (Part 3 Section B), Missouri Department of Revenue (Internet Archive capture). The private-pension income test reads Missouri AGI (MO-1040 line 6), which excludes the military retirement pay and capital gains subtracted on MO-A Part 1 (engine 1.8.0). Checked 2026-09-27.
2025 Form MO-1040 Instructions (MO-A Part 1 lines 10 and 18), Missouri Department of Revenue (Internet Archive capture). Missouri AGI subtracts the military retirement benefits and 100% of the federally reported capital gains. Checked 2026-10-12.

Public pensions

Public (government) pension dollars, entered as pensionPublic, are exempt up to $48,967 per person receiving it; dollars above the cap are taxed. On a joint return each spouse's own pensionPublic gets its own $48,967 when the spouse object gives the spouses' own amounts; without it the engine assumes the household's public pension is split between the spouses (up to $97,934 together). The exempt amount is reduced by the Social Security exemption: the federally taxable benefits of a person 62 or older, or of a younger person whose benefits are disability benefits or whose disability status is not said (the engine exempts those as disability benefits). They do not use up the capped exclusion that other retirement income may claim.

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

The MFJ cap of $97,934 is the engine's 2 x $48,967 per-taxpayer doubling (RSMo 143.124 'for each taxpayer on the combined return'); no page states $97,934.

RSMo 143.124 Public and private pensions exemption, Missouri Revisor of Statutes. From 2024 each taxpayer may subtract 100% of public-source retirement benefits up to the maximum Social Security benefit for the year, with no income or filing-status limit, reduced by any Social Security exemption claimed under 143.125. Checked 2026-10-12.
Pension FAQs, Missouri Department of Revenue. The maximum Social Security benefit that caps the Missouri public-pension exemption is $48,967 for tax year 2026, and the exemption is reduced by any Social Security deduction claimed. Checked 2026-10-12.
RSMo 143.124, Missouri Revisor of Statutes. The public-pension exemption is capped at the maximum Social Security benefit for the year, an indexed figure, so later years scale it. Checked 2026-10-12.

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".

MO 1040 Instructions 2025, Missouri Department of Revenue. Military retirement benefits are exempt, entered separately from the public and private pension exemptions. Missouri treats a survivor benefit plan annuity as a public pension. Checked 2026-10-12.
Military Reference Guide, Missouri Department of Revenue. Military retirement benefits are exempt, entered separately from the public and private pension exemptions. Missouri treats a survivor benefit plan annuity as a public pension. Checked 2026-10-12.

Roth conversions

A conversion is taxed as ordinary income in full. It does not draw any retirement-income exclusion.

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

No DOR page or form instruction addresses Roth conversions and the private-pension exemption directly; the engine's no-exemption reading rests on RSMo 143.124.11.

RSMo 143.121 Missouri adjusted gross income, Missouri Revisor of Statutes. Missouri adjusted gross income starts from federal AGI, so the taxable amount of a traditional-to-Roth conversion enters the Missouri base. Checked 2026-10-12.
RSMo 143.124 Public and private pensions exemption, Missouri Revisor of Statutes. Retirement benefits eligible for the pension exemptions exclude withdrawals rolled over into another retirement plan; the engine reads a conversion as such a rollover and does not let it draw the $6,000 private exemption. Checked 2026-10-12.

Capital gains

Long-term capital gains are not taxed, and neither are short-term gains (entered as shortTermGains).

RSMo 143.121 Missouri adjusted gross income, Missouri Revisor of Statutes. From tax year 2025 individuals subtract 100% of all income reported as a capital gain for federal purposes, long- and short-term, so Missouri taxes no capital gains. Checked 2026-10-12.
2025 Individual Income Tax Year Changes, Missouri Department of Revenue. The capital gains subtraction (Section 143.121) removes 100% of federally reported capital gains from Missouri AGI starting January 1, 2025. Checked 2026-10-12.
2025 Form MO-1040 Instructions (archived), Missouri Department of Revenue. The state return starts from federal adjusted gross income (federal taxable income in CO, IA, ND), so the federal capital-loss deduction (up to $3,000, $1,500 married filing separately) and its carryover are in the state base (engine 1.9.0: cap_loss_limit). Checked 2026-10-12.
2025 Schedule D (Form 1040), Capital Gains and Losses, Internal Revenue Service. The federal return deducts a net capital loss up to $3,000 ($1,500 married filing separately) on Form 1040 line 7a; a state that starts from federal adjusted gross income or federal taxable income carries that deduction. Checked 2026-10-12.

Interaction with the federal return

RSMo 143.171 (federal income tax deduction), Missouri Revisor of Statutes. A percentage of the federal income tax is deducted by Missouri AGI band (35% to $25,000, 25% to $50,000, 15% to $100,000, 5% to $125,000, none above), at most $5,000 ($10,000 combined) (engine 1.8.0). Checked 2026-10-12.
2025 Form MO-1040 Instructions (lines 9-13), Missouri Department of Revenue (Internet Archive capture). Line 13 multiplies the federal tax by the line 12 percentage, which is based on Missouri AGI (line 6). Checked 2026-10-12.

Blindness and disability

The standard deduction includes $2,050 more for a blind single or head-of-household filer and $1,650 more for each blind spouse on a married return. Age and blindness are separate: a person 65 or older and blind gets both amounts.
The API applies these through its blind, disabled, spouse.blind and spouse.disabled fields; absent means false.

2025 MO-1040 instructions (archived copy), Missouri Department of Revenue. Missouri's deduction is the federal one, with an amount for each condition: 65 or older, and blind. Checked 2026-10-12.
Rev. Proc. 2025-32 (2026 inflation adjustments), Internal Revenue Service. The federal additional standard deduction for 2026, per condition (age 65 and blindness each count): $2,050 unmarried, $1,650 married. The state takes it where its deduction is the federal one. Checked 2026-10-12.

Part-year and nonresident returns

Part-year resident (MO-NRI): the tax a full-year resident would owe on all the year's income, times the state's income ratio.
Nonresident (MO-NRI): the tax a full-year resident would owe on all the year's income, times the state's income ratio.
The ratio: the federal AGI of the state's income over the federal AGI of the whole year, rounded to 2 places, at most 1.
The ratio is a whole percent; under 0.5%, the exact percentage.
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.

Spouses	Missouri's rule
One spouse a full-year resident, the other a part-year resident	a joint part-year / nonresident return is required; each spouse's own income percentage applies to the tax on their own share of taxable income.
One spouse a full-year resident, the other a nonresident	a joint part-year / nonresident return is required; each spouse's own income percentage applies to the tax on their own share of taxable income.
One spouse a part-year resident, the other a nonresident	a joint part-year / nonresident return is required; each spouse's own income percentage applies to the tax on their own share of taxable income.
Both part-year residents, different resident periods	a joint part-year / nonresident return is required; each spouse's own income percentage applies to the tax on their own share of taxable income.
Both nonresidents, only one with income from the state	a joint part-year / nonresident return is required; each spouse's own income percentage applies to the tax on their own share of taxable income.

2025 Form MO-NRI, Missouri Income Percentage (with instructions), Missouri Department of Revenue. Part-year / nonresident return (engine 1.12.0, residency): MO-1040 lines 1-30 are computed as a full-year resident on total federal AGI; tax on line 30 is multiplied by the Missouri income percentage (line 32, from MO-NRI Part C line 3). Part-year residents may alternatively be taxed as full-year residents and claim the MO-CR credit for tax paid to the other state on income earned while living in Missouri. Checked 2026-10-12.
2025 Form MO-1040 Instructions, Missouri Department of Revenue. Part-year / nonresident return (engine 1.12.0, residency): MO-1040 lines 1-30 are computed as a full-year resident on total federal AGI; tax on line 30 is multiplied by the Missouri income percentage (line 32, from MO-NRI Part C line 3). Part-year residents may alternatively be taxed as full-year residents and claim the MO-CR credit for tax paid to the other state on income earned while living in Missouri. Checked 2026-10-12.
RSMo 143.181 Missouri nonresident adjusted gross income, Missouri Revisor of Statutes. Part-year / nonresident return (engine 1.12.0, residency): MO-1040 lines 1-30 are computed as a full-year resident on total federal AGI; tax on line 30 is multiplied by the Missouri income percentage (line 32, from MO-NRI Part C line 3). Part-year residents may alternatively be taxed as full-year residents and claim the MO-CR credit for tax paid to the other state on income earned while living in Missouri. Checked 2026-10-12.
2025 Form MO-1040 Individual Income Tax Long Form Instructions, Missouri Department of Revenue. Married couples whose residency differs (engine 1.13.0): Checked 2026-10-12.
2025 Form MO-NRI Missouri Income Percentage, Missouri Department of Revenue. Married couples whose residency differs (engine 1.13.0): Checked 2026-10-12.

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	$1,786.32
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	$2,568.87
Single, 60: $60,000 other ordinary income and a $50,000 Roth conversion	$4,232.67
Married filing jointly, 66: $30,000 IRA, a $40,000 Roth conversion, $30,000 Social Security ($25,500 federally taxable)	$1,440.87
Single, 58: $36,000 military retirement pay and $30,000 wages	$472.67
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	$1,048.42

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: $1,786.32

Line	Amount
Income total used by the income tests	$82,000
+ Other ordinary income in the base	$10,000
+ Retirement income in the base	$50,000
− Standard deduction	$18,150
= State taxable income	$41,850
Tax from the rate schedule	$1,786.32
= Tax before credits	$1,786.32
= Tax	$1,786.32

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: $2,568.87

Line	Amount
Income total used by the income tests	$144,000
Retirement income and conversions excluded (not in the base)	$6,000
+ Other ordinary income in the base	$20,000
+ Retirement income in the base	$74,000
− Standard deduction	$35,500
= State taxable income	$58,500
Tax from the rate schedule	$2,568.87
= Tax before credits	$2,568.87
= Tax	$2,568.87

Single, 60: $60,000 other ordinary income and a $50,000 Roth conversion: $4,232.67

Line	Amount
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	$16,100
= State taxable income	$93,900
Tax from the rate schedule	$4,232.67
= Tax before credits	$4,232.67
= Tax	$4,232.67

Married filing jointly, 66: $30,000 IRA, a $40,000 Roth conversion, $30,000 Social Security ($25,500 federally taxable): $1,440.87

Line	Amount
Income total used by the income tests	$95,500
+ Retirement income in the base	$30,000
+ Roth conversion in the base	$40,000
− Standard deduction	$35,500
= State taxable income	$34,500
Tax from the rate schedule	$1,440.87
= Tax before credits	$1,440.87
= Tax	$1,440.87

Single, 58: $36,000 military retirement pay and $30,000 wages: $472.67

Line	Amount
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	$16,100
= State taxable income	$13,900
Tax from the rate schedule	$472.67
= Tax before credits	$472.67
= Tax	$472.67

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: $1,048.42

Line	Amount
Income total used by the income tests	$85,500
+ Other ordinary income in the base	$10,000
+ Retirement income in the base	$50,000
− Standard deduction	$33,850
= State taxable income	$26,150
Tax from the rate schedule	$1,048.42
= Tax before credits	$1,048.42
= Tax	$1,048.42

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 Missouri's law moves it. Rates and the rules themselves stay the 2026 ones (how projection works).

Amounts (engine fields)	After 2026	What the law says, and the source
`brackets_single` (the single rate schedule's thresholds), `brackets_mfj` (the mfj rate schedule's thresholds)	Indexed: CPI-U (U.S.), 12-month average ending August 31 of the preceding year vs. the Sept 2014-Aug 2015 average (RSMo 143.011.6); not rounded (the statute states no rounding).	The single bracket table (all filers) is adjusted annually by the percent increase in CPI-U: the average CPI for the 12 months ending August 31 of the preceding year over the Sept 2014-Aug 2015 average. The statute states no rounding; DOR publishes whole-dollar edges. RSMo § 143.011 (Missouri Revisor of Statutes, statute): Subsections 5 and 6 index the brackets and define the CPI. Quoted: "the brackets of Missouri taxable income identified in subsection 1 of this section shall be adjusted annually by the percent increase in inflation"; ""CPI for the preceding calendar year", the average of the CPI as of the close of the twelve-month period ending on August thirty-first of such calendar year". Checked 2026-10-12.
`std_deduction_single`, `std_deduction_mfj`, `std_deduction_hoh`, `std_deduction_aged_add_unmarried`, `std_deduction_aged_add_married`, `blind_std_add_unmarried`, `blind_std_add_married`	Tied to an indexed federal amount: federal standard deduction under IRC 63(c) and the IRC 63(f) additional amounts for age/blindness, indexed by the IRC 1(f)(3) C-CPI-U cost-of-living adjustment; the increase rounded down to a multiple of $50.	The Missouri standard deduction is the allowable federal standard deduction (including the IRC 63(f) aged/blind additions), so it follows federal indexing (increases rounded down to $50). RSMo § 143.131 (Missouri Revisor of Statutes, statute): Missouri standard deduction = federal. Quoted: "The Missouri standard deduction shall be the allowable federal standard deduction.". Checked 2026-10-12. 26 U.S.C. 63 (Taxable income defined) (Legal Information Institute (Cornell) - U.S. Code, federal): IRC 63(c)(4) indexes the basic standard deduction and the subsection (f) additional amounts for age and blindness by the IRC 1(f)(3) cost-of-living adjustment. 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), subsection (f)(7) (Legal Information Institute (Cornell) - U.S. Code, federal): IRC 1(f)(7)(A): increases under 1(f)(2)(A) (brackets), 63(c)(4) (standard deduction) and 151(d)(4) are rounded down to a multiple of $50. Quoted: "section 63(c)(4), section 68(b)(2) [1] or section 151(d)(4) is not a multiple of $50, such increase shall be rounded to the next lowest multiple of $50". Checked 2026-10-12.
`retirement_income_exclusion_single`, `retirement_income_exclusion_mfj`, `retirement_exclusion_income_limit`, `retirement_exclusion_income_limit_mfj`, `retirement_exclusion_income_limit_mfs`	Fixed in law: held at the rules-year amount in every later year.	The private-pension subtraction is up to $6,000 per taxpayer with income ceilings of $25,000 (single/HOH), $32,000 (combined), $16,000 (MFS), reduced dollar for dollar above them; nominal in § 143.124.3-4, no inflation adjustment. RSMo § 143.124 (Missouri Revisor of Statutes, statute): Subsection 3 amounts. Quoted: "a maximum of the first six thousand dollars of any retirement allowance received from any privately funded sources for tax years beginning on or after January 1, 2002"; "Missouri adjusted gross income is less than twenty-five thousand dollars"; "combined Missouri adjusted gross income is less than thirty-two thousand dollars"; "Missouri adjusted gross income is less than sixteen thousand dollars". Checked 2026-10-12.
`public_pension_exclusion_cap_single`, `public_pension_exclusion_cap_mfj`	Indexed: CPI-U (U.S. Department of Labor), percentage increase year over year (RSMo 143.124.5); a statutory CPI series, not the actual SSA maximum benefit; not rounded (the statute states no rounding).	Public pension subtraction is capped at the 'maximum Social Security benefit available': $32,500 for 2007, increased each year by the percentage increase in CPI-U (no rounding stated). DOR publishes $48,967 for 2026. RSMo § 143.124 (Missouri Revisor of Statutes, statute): Subsection 5 defines and indexes the cap. Quoted: "the term "maximum Social Security benefit available" shall mean thirty-two thousand five hundred dollars for the tax year beginning on or after January 1, 2007, and for each subsequent tax year such amount shall be increased by the percentage increase in the Consumer Price Index for All Urban Consumers". Checked 2026-10-12. Pension FAQs (Missouri Department of Revenue, agency_page): Publishes the maximum Social Security benefit amount by year. Quoted: "2025 $47,633 2026 $48,967". Checked 2026-10-12.
`ss_exempt_min_age`	Attained age: the same age in every year.	Social Security benefits qualify when received by a taxpayer aged 62 or older (or as disability benefits); fixed attained age. RSMo § 143.125 (Missouri Revisor of Statutes, statute): Definition of benefits. Quoted: "any Social Security benefits received by a taxpayer age sixty-two years of age and older, or Social Security disability benefits". Checked 2026-10-12.
`hoh_additional_exemption`	Fixed in law: held at the rules-year amount in every later year.	Additional $1,400 for a head of household/surviving spouse; nominal in § 143.161.2, no adjustment. RSMo § 143.161 (Missouri Revisor of Statutes, statute): Subsection 2. Quoted: "may deduct an additional one thousand four hundred dollars". Checked 2026-10-12.
`eic_max_credit`, `eic_phaseout_start`, `eic_phaseout_start_mfj`	Tied to an indexed federal amount: federal EIC amounts under IRC 32 as in effect January 1, 2021 (pre-ARPA), indexed by IRC 32(j) with the IRC 1(f)(3) cost-of-living adjustment (chained CPI-U, Sept-Aug average); the increase rounded to the nearest $10.	The Working Family Tax Credit is a percentage of the federal EIC 'as such credit existed under 26 U.S.C. 32 as of January 1, 2021' - that frozen version keeps the IRC 32(j) indexing (earned-income/phase-out amounts to the nearest $10; investment-income limit, still on its pre-ARPA base, rounded down to $50). RSMo § 143.177 (Missouri Revisor of Statutes, statute): Credit is a percentage of the IRC 32 credit as of January 1, 2021. Quoted: "as such credit existed under 26 U.S.C. Section 32 as of January 1, 2021". Checked 2026-10-12. 26 U.S.C. 32 (Earned income credit) (Legal Information Institute (Cornell) - U.S. Code, federal): IRC 32(j) indexes the EIC earned-income and phase-out amounts (rounded to the nearest $10) and the disqualified-investment-income limit (rounded down to $50) by the IRC 1(f)(3) cost-of-living adjustment. Quoted: "each of the dollar amounts in subsections (b)(2) and (i)(1) shall be increased by an amount equal to"; "such dollar amount shall be rounded to the nearest multiple of $10"; "such amount shall be rounded to the next lowest multiple of $50". Checked 2026-10-12.
`eic_invest_limit`	Tied to an indexed federal amount: IRC 32(i)(1) disqualified investment income limit as in effect January 1, 2021, indexed under IRC 32(j) by the IRC 1(f)(3) cost-of-living adjustment (chained CPI-U, Sept-Aug average); the increase rounded down to a multiple of $50.	The disqualified investment income limit of IRC 32(i) as in effect January 1, 2021 (pre-ARPA base), indexed under IRC 32(j) and rounded down to $50. RSMo § 143.177 (Missouri Revisor of Statutes, statute): Frozen federal reference. Quoted: "as such credit existed under 26 U.S.C. Section 32 as of January 1, 2021". Checked 2026-10-12. 26 U.S.C. 32 (Earned income credit) (Legal Information Institute (Cornell) - U.S. Code, federal): IRC 32(j) indexes the EIC earned-income and phase-out amounts (rounded to the nearest $10) and the disqualified-investment-income limit (rounded down to $50) by the IRC 1(f)(3) cost-of-living adjustment. Quoted: "each of the dollar amounts in subsections (b)(2) and (i)(1) shall be increased by an amount equal to"; "such dollar amount shall be rounded to the nearest multiple of $10"; "such amount shall be rounded to the next lowest multiple of $50". Checked 2026-10-12.
`eic_nochild_max_age`, `eic_nochild_min_age`	Attained age: the same age in every year.	Under the IRC 32 as of January 1, 2021 a filer without a qualifying child must be at least 25 and under 65 at the close of the year (the ARPA 2021 age changes post-date the reference date); fixed ages. RSMo § 143.177 (Missouri Revisor of Statutes, statute): Frozen federal reference. Quoted: "as such credit existed under 26 U.S.C. Section 32 as of January 1, 2021". Checked 2026-10-12. 26 U.S.C. 32 (Earned income credit) (Legal Information Institute (Cornell) - U.S. Code, federal): IRC 32(c)(1)(A)(ii)(II): a filer without a qualifying child must be at least 25 and not yet 65 at the close of the taxable year. Quoted: "has attained age 25 but not attained age 65 before the close of the taxable year". Checked 2026-10-12.
`fit_pct_agi`, `fit_pct_cap_single`, `fit_pct_cap_mfj`	Fixed in law: held at the rules-year amount in every later year.	For tax years from 2019 the federal income tax deduction is a percentage (35/25/15/5/0%) set by Missouri gross income bands of $25,000 / $50,000 / $100,000 / $125,000, capped at $5,000 single or $10,000 combined; all nominal in § 143.171.2, no inflation adjustment. RSMo § 143.171 (Missouri Revisor of Statutes, statute): Subsection 2 table and caps. Quoted: "not to exceed five thousand dollars on a single taxpayer's return or ten thousand dollars on a combined return"; "$25,000 or less 35 percent From $25,001 to $50,000 25 percent From $50,001 to $100,000 15 percent From $100,001 to $125,000 5 percent $125,001 or more 0 percent". Checked 2026-10-12.
`cap_loss_limit`, `cap_loss_limit_mfs`	Fixed in law: held at the rules-year amount in every later year.	Missouri starts from federal AGI, so the fixed IRC 1211(b) limit applies. 26 U.S.C. 1211 (Limitation on capital losses) (Legal Information Institute (Cornell) - U.S. Code, federal): IRC 1211(b) limits a non-corporate capital loss against other income to $3,000 ($1,500 MFS), with no inflation adjustment. Quoted: "(1) $3,000 ($1,500 in the case of a married individual filing a separate return), or". Checked 2026-10-12.
`mo-property-tax-credit` (a table held in code)	Indexed: CPI-U Midwest Region (RSMo 135.025); the increase rounded to the nearest $1.	RSMo 135.025 / 135.030: the 2026 caps and upper limits are adjusted annually for inflation from 2027 (CPI-U Midwest). RSMo 135.030 Formula for determining credits (effective 28 Aug 2025; A.L. 2025 H.B. 594 & 508) (Missouri Revisor of Statutes (Missouri General Assembly), statute): Missouri Property Tax Credit (MO-PTS, 'circuit breaker') for tax year 2026 as amended by HB 594 & 508 (2025): exact statutory computation Quoted: "For all calendar years beginning on or after January 1, 2026, the maximum upper limit shall be the sum of:"; "Thirty-eight thousand two hundred dollars for claimants with a filing status of single;". Checked 2026-10-12. RSMo 135.025 Accrued taxes and rent constituting taxes to be totaled (effective 28 Aug 2025) (Missouri Revisor of Statutes, statute): Missouri Property Tax Credit (MO-PTS, 'circuit breaker') for tax year 2026 as amended by HB 594 & 508 (2025): exact statutory computation Quoted: "up to one thousand fifty-five dollars in rent constituting property taxes actually paid or one thousand five hundred fifty dollars in actual property tax paid,"; "Beginning January 1, 2027, the property tax credit totals under this section shall be adjusted annually for inflation". Checked 2026-10-12.

Enacted for later years, not applied by the projection

The top income tax rate (4.7% for 2026) may be cut by 0.1 point per year, up to the remaining reductions allowed under 143.011.4 (no more than three in total), each only if net general revenue beats the prior three-year high by $200 million (inflation-adjusted) and beats the five-years-prior amount adjusted for inflation. (2027+; conditional)
- RSMo § 143.011 (Missouri Revisor of Statutes, statute): Subsection 4 revenue-triggered cuts. Quoted: "Each reduction in the top rate of tax shall be by one-tenth of a percent and no more than one reduction shall occur in a calendar year. No more than three reductions shall be made under this subsection.". Checked 2026-10-12.
The Working Family Tax Credit may rise from 10% to up to 20% of the federal EIC if net general revenue beats the prior three-year high by $150 million. (2027+; conditional)
- RSMo § 143.177 (Missouri Revisor of Statutes, statute): Subsection 3(2)-(3). Quoted: "shall be ten percent, which may be increased to twenty percent subject to the provisions of subdivision (3) of this subsection". Checked 2026-10-12.

What the engine does not calculate, and known approximations

A Roth conversion does not draw the $6,000 private-pension exemption (the conservative reading of an unsettled question).
federalTax is the year's federal income tax after credits (MO-1040 lines 9-11); the deduction's percentage band reads Missouri AGI.
The Working Family Tax Credit is 20% of the federal earned income credit (the increased rate); the federal credit's investment-income limit is the Missouri instructions' $4,400, not the 2026 federal figure (engine 1.8.0, DIFF-MO-03).
Missouri deductions that need expenses or facts the inputs do not carry are not calculated: long-term care insurance premiums, health care sharing ministry contributions and the foster parent deduction. Sources: RSMo 143.131 Missouri standard deduction, when used, amount (checked 2026-10-12); 2026 Missouri Withholding Tax Formula (checked 2026-10-12); 2025 Form MO-1040 Instructions (checked 2026-10-12); Rev. Proc. 2025-32 (2026 inflation adjustments) (checked 2026-10-12); RSMo 143.161 (additional exemptions) (checked 2026-10-12); 2025 Form MO-1040 Instructions (line 15) (checked 2026-10-12); 2025 Form MO-PTS Property Tax Credit Schedule (checked 2026-10-01); RSMo 135.030 Formula for determining credits (effective 28 Aug 2025, A.L. 2025 H.B. 594 & 508) (checked 2026-10-12); RSMo 135.010 Definitions (effective 28 Aug 2025) (checked 2026-10-12); RSMo 135.025 Accrued taxes and rent constituting taxes to be totaled (effective 28 Aug 2025) (checked 2026-10-12); RSMo 135.020 Credits, how applied, considered overpayment (checked 2026-10-12); SS#2 for HCS for HB 594 & 508 (2025), Truly Agreed To and Finally Passed (1683S.04T) (checked 2026-10-12).
Married filing combined without a spouse object: the rate chart is applied once to the couple's taxable income, as if one spouse had all of it, so a couple whose income is split between them is overstated; with the spouse's own amounts each spouse is taxed on their share (lines 7 and 27). The form rounds each share to a whole percent; the engine uses the exact share. Sources: 2026 Missouri Withholding Tax Formula (checked 2026-10-12); RSMo 143.011 Resident individuals - tax rates (checked 2026-10-12); 2025 Form MO-1040 Instructions (lines 7, 27, 30) (checked 2026-10-12).
Form MO-A additions and subtractions for income the inputs do not separate are not calculated: interest from other states' and their localities' bonds (added), and interest from exempt federal obligations, a state income tax refund included in federal income, 529 and ABLE contributions and qualified health insurance premiums (subtracted). Sources: RSMo 143.131 Missouri standard deduction, when used, amount (checked 2026-10-12); 2026 Missouri Withholding Tax Formula (checked 2026-10-12); 2025 Form MO-1040 Instructions (checked 2026-10-12); Rev. Proc. 2025-32 (2026 inflation adjustments) (checked 2026-10-12); RSMo 143.161 (additional exemptions) (checked 2026-10-12); 2025 Form MO-1040 Instructions (line 15) (checked 2026-10-12); 2025 Form MO-PTS Property Tax Credit Schedule (checked 2026-10-01); RSMo 135.030 Formula for determining credits (effective 28 Aug 2025, A.L. 2025 H.B. 594 & 508) (checked 2026-10-12); RSMo 135.010 Definitions (effective 28 Aug 2025) (checked 2026-10-12); RSMo 135.025 Accrued taxes and rent constituting taxes to be totaled (effective 28 Aug 2025) (checked 2026-10-12); RSMo 135.020 Credits, how applied, considered overpayment (checked 2026-10-12); SS#2 for HCS for HB 594 & 508 (2025), Truly Agreed To and Finally Passed (1683S.04T) (checked 2026-10-12).
The Property Tax Credit (MO-PTS) uses the statute's formula on the exact amounts; the Department's chart rounds income to the midpoints of its brackets, so a chart-filed credit can differ by a few dollars. Sources: RSMo 143.131 Missouri standard deduction, when used, amount (checked 2026-10-12); 2026 Missouri Withholding Tax Formula (checked 2026-10-12); 2025 Form MO-1040 Instructions (checked 2026-10-12); Rev. Proc. 2025-32 (2026 inflation adjustments) (checked 2026-10-12); RSMo 143.161 (additional exemptions) (checked 2026-10-12); 2025 Form MO-1040 Instructions (line 15) (checked 2026-10-12); 2025 Form MO-PTS Property Tax Credit Schedule (checked 2026-10-01); RSMo 135.030 Formula for determining credits (effective 28 Aug 2025, A.L. 2025 H.B. 594 & 508) (checked 2026-10-12); RSMo 135.010 Definitions (effective 28 Aug 2025) (checked 2026-10-12); RSMo 135.025 Accrued taxes and rent constituting taxes to be totaled (effective 28 Aug 2025) (checked 2026-10-12); RSMo 135.020 Credits, how applied, considered overpayment (checked 2026-10-12); SS#2 for HCS for HB 594 & 508 (2025), Truly Agreed To and Finally Passed (1683S.04T) (checked 2026-10-12).

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 and unit tests follow Form MO-A Part 3 Sections A, B and C line by line, including the per-spouse columns.

Golden scenarios (hand-computed expected tax, asserted to within $1): MO01, MO02, MO-public-pension-capped, MORAMP1, MOSS1, MOPUBSS1, MOPUBSS2, MOSP1, MOSP2.
State-specific unit tests: test_mo_capital_gains_exempt, test_mo_pension_phaseout, test_mfs_one_schedule_states, test_mo_public_pension_capped, test_mo_private_worksheet_mechanics, test_mo_public_pension_ss_offset, test_mo_per_spouse_sections_a_b, test_mo_incoherent_split_regression, test_localities_endpoint, test_credit_programs_3, test_prop_l3_1140, test_replay_mo_columns, test_mo_ssdi_offset_under_62, test_split_path_without_ages, test_engine_180_s3, test_legacy_request_equals_v2, test_equal_ages_split_matches_legacy_split, test_mo_ss_offset_per_spouse, test_mo, test_worked_ratios, test_ratio_rules, test_hoh_federal_deduction_states, test_mo_aged_additional_deduction.
Structural tests covering every state: 9.
State forms and worksheets followed in the test derivations: Form MO-A Part 3, Sections A, B and C.