Locum Tenens Taxes in Michigan

A nonresident who earned income from services performed in Michigan files the standard MI-1040 with Schedule NR, which allocates income between Michigan and everywhere else so the flat rate lands only on the Michigan-source portion. Michigan sources compensation for personal services to where the work is physically performed, and there is no minimum-day safe harbor for paid 1099 work: a short assignment at a Michigan hospital creates Michigan-source income for those days.

As in every state guide in this series, the allocation is a working-days fraction, Michigan days over total days for the engagement, and the defense is a contemporaneous calendar backed by shift schedules and credentialing records.

Michigan has reciprocal income tax agreements with Illinois, Indiana, Kentucky, Minnesota, Ohio, and Wisconsin. Under them, a resident of one state who earns salaries and wages in the other pays income tax only to their home state on that compensation. For W-2 locum physicians who live across the border, this is genuinely great: an Ohio-resident hospitalist on a W-2 contract in Ann Arbor pays Ohio, not Michigan, on those wages, and can file to recover any Michigan withholding taken in error.

The catch is the scope. The agreements cover employee compensation, salaries and wages, and not business income. A 1099 independent contractor is earning business income from Michigan activity, which the agreements leave fully taxable by Michigan. Same physician, same hospital, same shifts: the W-2 version pays only Ohio; the 1099 version files a Michigan nonresident return, pays Michigan 4.25% on the Michigan-source income, and claims Ohio's resident credit. The contract form, not the geography, decides the outcome.

Roughly 24 Michigan cities levy their own income taxes under a uniform state framework that sets nonresident rates at half the resident rate. Detroit is the big one: 2.4% for residents, 1.2% for nonresidents on income earned in the city. Most other taxing cities, including Lansing, Flint, Saginaw, Pontiac, and Hamtramck, charge 1% resident / 0.5% nonresident, with Grand Rapids among the few above the standard. Nonresidents owe city tax only on income earned inside the city limits, and that includes the net profits of a 1099 physician's business activity performed there.

Mechanically, Detroit's individual income tax is administered by the Michigan Department of Treasury, with nonresidents filing Form 5119 (the Detroit nonresident city return) alongside the state MI-1040. The other taxing cities administer their own returns on a common city form. None of this is hard, but each taxing city where you worked is potentially one more return, so the time to notice is when you accept the assignment, not in April.

W-2 agencies generally withhold Michigan state tax (and, where registered, city tax) on wages for Michigan work. 1099 physicians get nothing withheld. Michigan expects quarterly estimated payments via Form MI-1040ES once you anticipate owing $500 or more for the year, a bar any real Michigan assignment clears. Taxing cities have their own parallel estimated-payment rules for nonresidents with significant city-source income, including Detroit.

The working habit: set aside 4.25% of every Michigan gross payment for the state, plus the city rate for facility cities that tax, in the same account as your federal set-aside. At Michigan's rates that discipline is cheap; underpayment penalties and a two-return catch-up in April are not.

Michigan adds no entity-level penalty to the locum S-corp decision: no California-style franchise tax, no Tennessee-style excise trap. The usual federal self-employment tax analysis drives the choice, and Michigan's flat rate keeps the state layer predictable.

Michigan also offers an elective flow-through entity (FTE) tax: an S-corp or partnership can elect to pay Michigan tax at the entity level at the individual rate, with members claiming a corresponding credit on their MI returns. Like other states' PTET regimes, the point is federal: the entity-level payment is deductible without the individual SALT cap. For a nonresident locum whose entity has meaningful Michigan-source income, it is worth modeling, though the benefit depends on your federal itemizing picture and home-state credit interaction.

And the standing rule applies here too: the entity does not move the income. Michigan sources personal services income through to the physician who performed the work, and an out-of-state S-corp doing business in Michigan picks up its own Michigan obligations.

Illustrative example, not a specific client outcome. A Colorado-resident emergency physician earns $300,000 of 1099 income for the year, including $80,000 from a stretch of shifts at a hospital inside Detroit city limits. Reciprocity does not apply (Colorado is not a reciprocal state, and this is 1099 income anyway).