Indiana Tax Residency Rules 2026: The 183-Day Rule & County Tax

Who needs to read this

Indiana is a low-rate, low-drama tax state (a flat 2.95% state rate for 2026, headed to 2.90%), but its residency mechanics have two sharp edges: a 183-day statutory-resident test and a January 1 county-tax snapshot that keeps charging you after you've moved. Worth reading if:

• You moved into or out of Indiana during the year
• You commute across the border to or from Illinois, Kentucky, Michigan, Ohio, or Wisconsin
• You keep an Indiana second home or lake house while living elsewhere
• You're retiring south and want Indiana's claim to actually end
• You're changing counties, since your county rate is set once a year

How Indiana defines residency

Under Indiana Code §6-3-1-12, a resident is:

1. Any individual domiciled in Indiana during the taxable year, or
2. Any individual who maintains a permanent place of residence in Indiana and spends more than 183 days of the taxable year in the state.

The first prong is the ordinary rule: Indiana is your permanent home, so Indiana taxes everything. The second is the statutory-resident catch for people domiciled elsewhere: an Indiana home plus a majority of the year physically in Indiana makes you a resident regardless of where you claim to belong. Indiana's administrative rules (45 IAC 3.1-1-21) add that a person has only one domicile at a time, that an established domicile continues until a new one is acquired, and that acquiring one requires physical presence in the new place plus the simultaneous intent to make a home there.

Separately from state residency, your county matters: county income tax attaches based on your county of residence (or county of employment for nonresidents) as of January 1, and that determination holds for the entire year.

Counting the days

Days count toward Indiana's statutory test only alongside a maintained Indiana home, and they aggregate across the whole year:

• The statutory test needs both elements: a permanent place of residence maintained in Indiana and more than 183 days in the state. Days in Indiana without a maintained home, or a home without the days, don't trigger it.
• Regular presence adds up faster than people expect, especially for border-town patterns where "home" is one state and errands, work, and family are in the other.
• Indiana publishes no elaborate day-counting protocol, which cuts both ways: the DOR isn't subpoenaing cell records like New York, but if your status is questioned, the burden of showing where you were falls on your own records. A contemporaneous day log settles in minutes what reconstruction can't.

Domicile: the stickier test

Domicile is the permanent home you intend to return to, and Indiana applies the standard framework: it stays put until you actually establish a new one, with presence plus intent, together. Evidence the state looks at:

• Where your family lives and children attend school
• Whether you maintained a permanent place of residence in Indiana (the rules treat this as presumptive evidence of domicile)
• Driver's license, voter registration, and vehicle registration
• Where you claim a homestead deduction on property tax
• Employment, business interests, and the address on your federal return

The recurring Indiana fact pattern is the retiree who winters in Florida, keeps the Indianapolis house, the Indiana plates, and the homestead deduction, and is surprised that Indiana still considers itself home. Until the new state is established with intent and presence, it is.

Part-year residents and nonresidents

Which form you file follows your status: IT-40 for full-year residents, IT-40PNR for part-year residents and nonresidents, IT-40RNR for reciprocal-state wage earners.

• Full-year residents file Form IT-40 and pay tax on all income.
• Part-year residents and nonresidents file Form IT-40PNR: all income while resident, plus Indiana-source income (Indiana workdays, rentals, business income) while nonresident.
• Reciprocal-state residents (Kentucky, Michigan, Ohio, Pennsylvania, Wisconsin) pay their home state, not Indiana, on Indiana wages, salaries, tips, and commissions, filing Form IT-40RNR. Any other Indiana-source income pushes them to IT-40PNR, and reciprocity does not cancel Indiana county tax, which can still apply via the January 1 county-of-employment rule.

Rates: the state rate is 2.95% for 2026, dropping to 2.90% in 2027. County rates vary by county and are published in DOR's Departmental Notice #1, updated in January and October.

Changing your residency status

A clean Indiana exit or entry comes down to establishing the new domicile affirmatively and unwinding the old anchors promptly:

• Establish the new domicile affirmatively: physical presence plus intent, evidenced by a new home, new license and registrations within the new state's deadlines, and voter re-registration
• Unwind the Indiana anchors: drop the homestead deduction, re-register vehicles, update the address on federal filings
• If you keep an Indiana home, watch the 183-day line; the statutory test doesn't care where your paperwork says you live
• Time county moves around January 1. The county snapshot is taken once: leaving an Indiana county (or the state) just after New Year's means that county's tax applies for the whole departing year
• File IT-40PNR for the split year with a consistent move date on the return

How Indiana enforces its rules

Indiana's enforcement is routine rather than aggressive: matching-notice territory, not forensic reconstruction.

• Paper cross-checks do the work: W-2 addresses, homestead deductions, vehicle and voter records, and federal return addresses that disagree with a claimed exit
• The homestead deduction is a particular tripwire: claiming a property-tax break reserved for your principal Indiana residence while filing as a nonresident is self-contradiction the state can see without an audit
• County-tax errors are the most common residency-adjacent notice: wrong county claimed, or the January 1 snapshot misapplied after a move
• Stakes are lower than in high-rate states, but reclassification still means state plus county tax on all income, with penalties and interest

Common mistakes

• Treating 183 days as the only test. Domicile alone makes you a resident at any day count; the 183-day rule is a second net, not the definition.
• Ignoring the January 1 county snapshot. Moving on January 2 leaves you paying the old county's rate (or Indiana county tax after leaving the state entirely) for the full year.
• Keeping the homestead deduction after "moving out." It's presumptive evidence your domicile never left, and it's sitting in a database.
• Assuming reciprocity covers everything. IT-40RNR handles wages only: Indiana rentals or business income mean IT-40PNR, and county tax can still apply.
• The unfinished exit. Florida winters with Indiana license, plates, and voter registration intact leave your domicile, and Indiana's claim, exactly where it was.
• No records at the margin. Border commuters and second-home owners near 183 days win or lose on documentation they usually haven't kept.