Stacked vs. Single-Policy UM/UIM Coverage in Michigan

By the FigureMyTax Editorial Team · How we calculate

Stacking adds the uninsured and underinsured motorist limits of several vehicles or policies together. Michigan has no statute on UM/UIM, so whether limits stack depends on your policy wording.

What stacking means

A household may have more than one vehicle or policy with UM or UIM. Stacking adds those limits after one injury, so $100,000 and $50,000 become $150,000. Single-policy coverage pays only the one limit that applies.

What the statutes say

Michigan's uninsured motorist statute, MCL 500.3010, was repealed by Act 345 of 1972, effective October 1, 1973. No statute we found requires UM or UIM coverage or addresses stacking, so the rules come from your policy and from court decisions that read it.

What we could not confirm

We did not read Michigan court decisions on how clear anti-stacking language is enforced, or on how "other insurance" clauses work, so we do not assume either rule. Ask an attorney, and ask your insurer in writing which limits it says apply.

A worked example

Suppose you are insured under two policies with $100,000 and $50,000 of UIM, the at-fault driver's $50,000 was paid, and your damages are $250,000. If your coverage applies on top of that payment and only the first limit counts, UIM pays $100,000. If the limits combine, it could pay $150,000. If your coverage is reduced by the other driver's limit, the first policy pays $50,000. Try your own numbers in the Michigan UM/UIM stacking calculator.

What to check

Read the UM/UIM endorsement and the limit-of-liability and other-insurance clauses of each policy, and note whether you are a named insured, a household member or a passenger. See what the statutes say and leave open and how UM and UIM work under Michigan no-fault.

This is general information, not legal advice, and the state comparisons above are illustrative, not an exhaustive survey. Confirm how Michigan's rules apply to your specific case with a licensed Michigan attorney.