Stacked vs. Standard UM Coverage in Maryland

By the FigureMyTax Editorial Team · How we calculate

Maryland bars recovering ordinary UM benefits from more than one policy, and standard UM is reduced by what the at-fault driver's coverage paid. Enhanced underinsured motorist coverage is the exception: it is not reduced, so it works on top of that payment.

What stacking means

A household may have more than one policy or vehicle with UM coverage. Stacking adds those limits, or adds your limit on top of what the at-fault driver paid. Maryland handles the two ideas separately.

Across policies

Insurance Article 19-513(b) says that notwithstanding any other provision of the subtitle, a person may not recover UM benefits from more than one motor vehicle liability policy or insurer on a duplicative basis, and, except as provided in section 19-509.1, may not do so on a supplemental basis.

On top of the other driver's payment

Under standard UM, your insurer's limit is your coverage less the amount paid to you by the liability coverage that exhausts the at-fault driver's policies (19-509(g)). Under enhanced underinsured coverage, the limit is the full coverage amount without any reduction for that payment (19-509.1(h)).

A worked example

Suppose you have $100,000 of coverage, the at-fault driver's $30,000 liability limit is paid, and your damages are $250,000. Standard UM pays $100,000 less $30,000 = $70,000. Enhanced underinsured coverage pays the full $100,000, so you receive $130,000 in total. Try your own numbers in the Maryland UM/UIM stacking calculator.

What to check

Ask your insurer which coverage your policy has. For new private passenger policies the statute now requires the insurer to provide enhanced underinsured coverage unless the first named insured affirmatively waives it in writing on the Commissioner's form. A law-firm article describes the 2018 introduction of the option; the statute has since changed from an offer to a default, so rely on the statute. See what 19-513 and 19-509.1 say and how UM and enhanced coverage differ.

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