Car loan interest deduction in Michigan
The car loan interest deduction is a federal benefit. What it means for your Michigan return depends on whether Michigan taxes income and how it follows the federal rules.
The federal car loan interest deduction (tax years 2025–2028) applies in Michigan the same as anywhere — if your vehicle is new, personal-use, US-assembled, financed with a 2025–2028 loan, and your income is under the phase-out. Whether it also lowers your Michigan state tax depends on state conformity — see below.
Michigan income tax at a glance
- State income tax
- 4.25% flat
- Return starts from federal AGI
- Yes — starts from federal AGI
- Conformity to federal changes
- Hybrid rule
- State tax agency
- Michigan Department of Treasury
How state conformity works
Because the deduction is above-the-line, it reduces your federal adjusted gross income (AGI). Whether that also lowers your Michigan taxable income depends on how Michigan conforms to the federal tax code:
- Rolling conformity: the state automatically adopts federal changes as they happen, so a new above-the-line deduction like this one generally flows through to the state return.
- Static (fixed-date) conformity: the state only adopts the federal code as of a set date, so a brand-new 2025 provision does not flow through until the state updates that date — you may get the federal deduction but no state benefit.
Michigan has a hybrid conformity rule, so whether this 2025 federal deduction reaches your Michigan return is not automatic. Confirm the current treatment with the Michigan Department of Treasury.
This reflects Michigan's general conformity method, not a ruling on this specific deduction — always confirm the current year with the Michigan Department of Treasury or a tax professional.
Your combined federal + Michigan saving
The deduction is a deduction, not a credit — it saves you your marginal rate on the qualifying interest, not the interest itself. Federally that's your IRS bracket; in Michigan, at a top rate of 4.25%, the deduction adds a state saving only if the state adopts this 2025 provision. Estimate both:
Confirm your federal eligibility first
State treatment only matters if you qualify federally. Check the three tests that trip people up: