How Kansas income tax works: federal AGI, Schedule S, two brackets

Kansas taxes income in two steps that most people never see separated. Form K-40 starts from federal adjusted gross income, line 11 of Form 1040, not from federal taxable income. Everything the federal return does after that line, the standard deduction, itemized deductions, the senior, tips and overtime deductions, the qualified business income deduction, is invisible to Kansas. The state then applies its own machinery: Schedule S additions and subtractions, a Kansas standard or itemized deduction, a personal exemption of $9,160 per filer ($18,320 joint) plus $2,320 for each dependent, and two rates, 5.2% on the first $23,000 of taxable income ($46,000 joint) and 5.58% above. A 2025 law was meant to push those rates toward a flat 4%, but its revenue trigger has not fired, so the 2026 return uses the same rates as 2024 and 2025.

The starting point has consequences. A federal deduction taken below the AGI line is worth nothing in Kansas, which is why a server who owes no federal tax on $8,000 of tips still owes Kansas $416 to $446 on them. A federal adjustment taken above the line, an IRA contribution, an HSA deposit, flows through and cuts Kansas tax too. And because Kansas has its own deduction and exemption system on top of AGI, the retiree who pays federal tax on a KPERS pension pays Kansas nothing on it, and the homeowner who took the federal standard deduction may still itemize for Kansas.

Who files

A Kansas resident is anyone domiciled in Kansas; the Department of Revenue puts it as anyone who lives in Kansas, regardless of where they work. Residents report all income from everywhere and take a credit on line 13 for tax paid to another state. Part-year residents and nonresidents allocate on Schedule S Part B. Kansas has no reciprocal agreement with any state, so a Kansas resident working across the Missouri line files in both states every year. The details are in Moving to Kansas.

A resident must file when required to file a federal return, or when Kansas gross income exceeds the standard deduction plus exemptions ($12,765 single, $26,560 joint with both under 65). Below that it still pays to file to recover withholding or claim the earned income credit.

Where it starts: federal AGI

Line 1 of the K-40 is federal adjusted gross income, copied from Form 1040: income after the Schedule 1 adjustments but before the standard deduction and everything beneath it. So the federal standard deduction never reaches Kansas. Neither does the extra federal standard deduction for age, the $6,000 federal senior deduction, the deductions for tips, overtime and car-loan interest, the non-itemizers’ charitable deduction, or the 20% qualified business income deduction. None of them needs a Kansas add-back, because none of them was ever taken out.

Kansas conforms to the Internal Revenue Code as amended, so a federal change at or above the AGI line takes effect automatically; the July 2025 federal law changed the return mostly below that line, which is why so little of it shows up on the K-40. See What is new in Kansas for 2026.

Schedule S, Part A: additions

Line 2 of the K-40 carries the net modification from Schedule S. Most households have one addition or none.

Other states’ municipal bond interest (A1). Kansas bonds stay exempt; other states’ bonds are added. A brokerage 1099 that lumps all municipal interest together has to be split.

KPERS contributions (A2). A state or school employee’s own contributions to the Kansas Public Employees Retirement System come out of federal wages before tax. Kansas adds them back here, usually from Box 14 of the W-2. Because the contributions are taxed by Kansas going in, the KPERS pension is exempt coming out.

Schedule S, Part A: subtractions

This is where the Kansas return gives money back.

Private pensions, IRAs, 401(k)s and annuities are not on the list. Kansas taxes them in full, at any age. The split between what is subtracted and what is not is the whole story of Kansas for retirees.

Social Security, line A10. Every dollar of Social Security in federal AGI comes off here; the old $75,000 AGI limit was removed in 2024. Public pensions, line A14. Subtracted in full; a private pension, IRA or 401(k) is not. 529 and ABLE contributions, lines A16 and A21. Up to $3,000 per beneficiary a year, $6,000 joint, for Learning Quest or any other state’s plan. Because the federal return asks nothing about 529 deposits, this is the subtraction most often left off.

Deduction: standard or Kansas itemized

Line 4 is where Kansas does something unusual. The Kansas standard deduction is small and fixed by statute: $3,605 single, $8,240 married filing jointly, $6,180 head of household, $4,120 married filing separately, plus $850 (single or head of household) or $700 (married) for each federal additional standard deduction for age 65 or blindness. A married couple both over 65 gets $9,640. None of it is indexed, so the 2025 figures carry straight into 2026.

In place of that, you may claim Kansas itemized deductions on Schedule A, and the statute says you may do so “regardless of whether or not” you itemized federally. They are 100% of exactly four federal items: charitable gifts, medical expenses above the federal 7.5% floor, home mortgage interest, and real and personal property taxes. There is no deduction for state income tax, so the federal $40,000 SALT cap has nothing to cap here, and none for gambling losses, investment interest or anything else.

The arithmetic favors itemizing more often than people expect. A homeowner with $9,000 of mortgage interest and $4,000 of property tax has $13,000 of Kansas itemized deductions against a $3,605 or $8,240 standard deduction, even if the federal return used the $32,200 federal standard deduction. Self-prepared returns often take the Kansas standard deduction by default. Married couples filing separately must choose the same way.

The exemptions

Line 5 is the personal exemption, and it does the work a standard deduction does elsewhere: $9,160 for a single, head of household or married-separate filer, $18,320 married filing jointly, and $2,320 for each dependent claimed on the federal return. Three more $2,320 exemptions apply for 2025 and after: for a head of household filer, for a child born during the year (or a certified stillbirth), and for a veteran certified 100% service-connected disabled. There is no income limit and no phase-out.

The rates

AGI, plus or minus Schedule S, is Kansas adjusted gross income (line 3). Less the deduction and the exemptions, it is Kansas taxable income (line 7). The tax is 5.2% of the first $23,000 for single, head of household and married-separate filers, or $46,000 for joint filers, and 5.58% of the rest: $1,196 plus 5.58% of the excess over $23,000, or $2,392 plus 5.58% of the excess over $46,000. Capital gains, dividends, interest, gambling winnings and unemployment are taxed at the same rates as wages.

Those rates came from the 2024 special session, which collapsed three brackets into two. A 2025 law, SB 269, then set up a trigger: each August 15 the state checks whether general fund receipts beat an inflation-adjusted base and whether the rainy-day fund holds at least 15% of the prior year’s tax receipts; if both pass, the Department publishes lower rates, stepping toward a 4% floor. The revenue test failed in August 2025 (receipts $88.5 million short) and again in August 2026 ($214.3 million short, even with the rainy-day fund at 20.4%). No cut for 2026, none for 2027. Anyone who heard that Kansas is going to a flat tax should know that nothing has happened yet.

Kansas has no local income tax on wages. A handful of counties, cities and townships levy a local intangibles tax on interest and dividends, filed on Form 200 with the county clerk, not with the K-40; most Kansans live where none applies.

The credits

The food sales tax credit ended after 2024. Kansas has no child tax credit; each child is a $2,320 exemption instead. See Credits and breaks for Kansas families.

Separate from the K-40, and often worth more than anything on it for an older homeowner, are three property tax refunds: the homestead refund (K-40H, up to $700), SAFESR (K-40PT) and the senior and disabled veteran “freeze” (K-40SVR), claims filed with the Department between January 1 and April 15 for a home appraised at $350,000 or less. They are explained in Kansas for retirees.

Withholding and estimated payments

Kansas withholding on wages is figured from Form K-4, the state’s own certificate: the employee picks the single or joint rate and claims allowances, one for self, one for a non-working spouse, two for head of household, one per dependent, with line 5 for a flat extra amount. Because each K-4 assumes it is the only job, a two-earner couple should claim the allowances on one job and zero on the other.

Estimated payments on Form K-40ES are required when the Kansas tax expected after withholding and credits is $500 or more, due April 15, June 15, September 15 and January 15. The safe harbors match the federal ones, 90% of this year’s tax or 100% of last year’s, and the penalty is figured on Schedule K-210. The people usually caught are the self-employed, landlords, anyone with a large capital gain, and retirees living on IRA withdrawals and private pensions, since payers rarely withhold Kansas tax from those.

How to file

Most Kansas returns are filed electronically with the federal return; Kansas WebFile, the Department’s own free system, files the K-40 directly with direct deposit, and Homestead WebFile does the same for the property tax refund claims. The return is due April 15, 2027. Kansas has no extension form: attach a copy of federal Form 4868 to the K-40 for an automatic extension to file, not to pay. Pay at least 90% of the tax by April 15 or the late-payment penalty runs at 1% a month to a maximum of 24%, with interest at 0.6667% a month on top. Paper refunds can take months, so e-file with direct deposit. Dates and forms are in Kansas calendar and forms.

What trips people up

• Taking the Kansas standard deduction because the federal return did. The bar is only $3,605 or $8,240.
• An IRA or private pension treated as exempt because Social Security and KPERS are.
• A Learning Quest contribution nobody mentioned, because the federal return did not ask.
• The credit for tax paid to Missouri claimed from the W-2 alone. The Department wants the other state’s return.
• The extension treated as an extension to pay.