Stacked vs. Single-Limit UM/UIM Coverage in Maine

By the FigureMyTax Editorial Team · How we calculate

Stacking adds the uninsured vehicle coverage limits of several policies or vehicles together. Maine's statute does not address it, so the answer turns on your policy wording and Maine case law.

What stacking means

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

What the statute says

24-A MRSA 2902 requires uninsured vehicle coverage, which covers uninsured, underinsured and hit-and-run vehicles, and sets the required limits and how underinsured coverage is calculated. It says nothing about adding limits across several vehicles or policies, or about "other insurance" or anti-stacking clauses.

What we could not confirm

We searched for a Maine Supreme Judicial Court decision on stacking we could read and did not find a controlling one. Secondary commentary on other states shows courts split widely, from enforcing clear anti-stacking clauses to voiding them, so we do not assume either rule for Maine. Ask an attorney, and ask your insurer in writing which limits it says apply.

A worked example

Suppose you are an insured under two policies with $100,000 and $50,000 of UIM, the at-fault driver's $50,000 liability limit was paid, and your damages are $250,000. If only the highest limit counts, UIM pays $100,000 less $50,000 = $50,000. If both limits stack, it could be $150,000 less $50,000 = $100,000. Try your own numbers in the Maine UM/UIM stacking calculator, which shows both.

What to check

Read the uninsured vehicle section and the "other insurance" or limit-of-liability clause of each policy, and note whether you are a named insured, a household member or a passenger. See what section 2902 says and leaves open and how Maine's uninsured vehicle coverage works.

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