Locum Tenens Taxes in Indiana

If you are not an Indiana resident but you earned income from services performed inside Indiana, you generally must file Form IT-40PNR, Indiana's Part-Year and Full-Year Nonresident Individual Income Tax Return. This applies whether you were paid 1099 directly, through a staffing agency, or through your own S-corp or LLC that assigned you to an Indiana facility.

Indiana, like most states, sources compensation for personal services to where the work is physically performed. There is no day-count safe harbor for 1099 personal services income; a two-week hospitalist stretch in Fort Wayne creates Indiana-source income for those two weeks. Because the flat rate is low, the resulting bill is often small, but the filing obligation is real, and skipping it creates notice and penalty exposure out of proportion to the tax involved.

Every Indiana county imposes a local income tax on top of the state rate. For an Indiana resident, the county of residence on January 1 controls for the entire year. For a nonresident, the question is different: were you maintaining your principal place of business or employment in an Indiana county on January 1? If yes, that county's nonresident tax applies to your Indiana-source income for the whole year. If no, the county layer generally does not apply for that year at all.

For a locum physician, this produces two very different outcomes from the same assignment, depending purely on timing:

Indiana has reciprocal agreements with Kentucky, Michigan, Ohio, Pennsylvania, and Wisconsin. Under these agreements, a resident of one of those states who earns wages, salaries, tips, or commissions in Indiana pays income tax only to their home state on that compensation. Residents of those states whose only Indiana income is W-2 wages file the short Form IT-40RNR instead of the full nonresident return.

Here is the part that matters for locums: reciprocity covers W-2 compensation only. Independent contractor income reported on a 1099 is outside the agreements entirely. A 1099 locum who lives in Cincinnati and covers shifts across the border in southeastern Indiana owes Indiana tax on that income, files Form IT-40PNR, and then claims a resident credit on the Ohio return. The reciprocity agreement never enters the picture.

This also means your pay structure changes your filing outcome. The same physician doing the same shifts as a W-2 employee of the agency would hand the whole state-tax question to Ohio under reciprocity. As a 1099 contractor, Indiana taxes the income first and Ohio cleans up with a credit. Neither is automatically better overall, but they are different, and locums who switch between W-2 and 1099 agency arrangements mid-year end up with both patterns in a single return season.

If you work an Indiana assignment as a W-2 employee, the agency generally withholds Indiana state tax, and county tax where it applies, from wages for work performed in Indiana (unless reciprocity applies because you live in one of the five agreement states). If you work as a 1099 independent contractor, nothing is withheld. The full Indiana liability accrues quietly until you file.

Indiana expects quarterly estimated payments, via Form ES-40 or the DOR's online system, if you will owe more than a small amount for the year with no withholding to cover it. Because the flat rate is low, the estimated payments on a single short assignment are often modest. The discipline still matters: locums working several Indiana blocks across a year can build up a four-figure liability, and underpayment penalties apply to balances that should have been paid in quarterly.

A lot of locum physicians run their practice through an S-corp for self-employment tax savings. In some states, that structure picks up a separate entity-level cost (California's $800 minimum and 1.5% franchise tax is the classic example). Indiana has no comparable general franchise tax or minimum entity tax, so the standard S-corp break-even math survives an Indiana assignment largely intact. The entity will have an Indiana filing obligation if it does business in the state, and Indiana's composite return and nonresident shareholder withholding rules can apply to pass-through income of nonresident owners.

Indiana also offers an optional pass-through entity tax (PTET) election, enacted in 2023 and retroactive to 2022. An electing S-corp or partnership pays Indiana tax at the entity level and the owners claim a refundable credit, which converts the state tax into a federally deductible business expense and works around the federal SALT deduction cap. Whether the election helps depends on your federal itemizing picture and how much of your income is Indiana-source; it is a modeling question, not a default.

Illustrative example, not a specific client outcome. Consider a 1099 emergency medicine locum who lives in Ohio and earns $280,000 of net 1099 income for the year. She works 30% of her days ($84,000 of income) at an Indiana hospital, starting in May and ending in September, and the rest in Ohio. She was not working in Indiana on January 1, so the county layer does not apply.