Inputs

The inputs are TAXSIM's, with the same names, meanings and units. Dollar amounts are annual and in nominal dollars of the tax year. Anything absent or null counts as 0, except where noted. Extra columns in your data are carried through to the result untouched.

Required

Column	Meaning
year	Tax year, 1960-2025. Not needed if you pass year= to calculate_taxes.
state	TAXSIM state code 1-51 (alphabetical, with DC as 9), or 0 for no state tax. With state_id_type="fips", Census FIPS codes.
mstat	Filing status: 1 single (head of household if depx > 0), 2 joint, 6 married filing separately, 8 dependent filer. The older codes 3, 33 and 66 are also accepted.

Household

Column	Meaning
taxsimid	Your case identifier. Optional and carried through.
page, sage	Age of the taxpayer and spouse (0 if none). Used for age-65 and similar provisions.
depx	Number of dependents.
dep13, dep17, dep18	Dependents under 13, 17 and 18 (child care, child tax credit and similar). Default to depx.
dep6, dep19	Dependents under 6 and under 19 (or students).
age1, age2, age3	Ages of up to three dependents. If any is present, the age counts above come from these.
children_under_3, children_under_4, children_under_7	Optional extensions for survey data. Not part of TAXSIM's inputs; default to 0.

Income

Column	Meaning
pwages, swages	Wages of the taxpayer and spouse.
psemp, ssemp	Self-employment income of the taxpayer and spouse. Gets no qualified business income deduction; use pbusinc/pprofinc for that.
dividends, intrec	Dividends and interest received.
stcg, ltcg	Short- and long-term capital gains.
otherprop	Other property income, subject to the net investment income tax.
nonprop	Other non-property income, such as alimony received.
pensions	Taxable pensions and IRA distributions.
gssi	Gross Social Security benefits.
pui, sui	Unemployment compensation of the taxpayer and spouse. ui is the combined older form.
transfers	Non-taxable transfers, which count for state benefits tests.
scorp	S-corporation income.
pbusinc, sbusinc	Qualified business income of the taxpayer and spouse.
pprofinc, sprofinc	Qualified business income from specified service trades.

Deductions and expenses

Column	Meaning
rentpaid	Rent paid (for state renter credits).
proptax	Real estate taxes paid.
otheritem	Other itemized deductions, such as state and local taxes, medical expenses and charity.
childcare	Child care expenses.
mortgage	Mortgage interest and other deductions that are not subject to the usual limits.

Calculation controls

Column	Meaning
mtr	Marginal-rate code per row (see Calculating).
idtl	2 for the detailed worksheets on that row.

!!! note Two conventions to know: psemp/ssemp get no qualified business income deduction (use pbusinc/pprofinc), and pensions is treated as the kind of pension each state exempts.