Stacked vs. Unstacked UM/UIM Coverage in the District of Columbia

By the FigureMyTax Editorial Team · How we calculate

Stacking adds the uninsured and underinsured motorist limits of several vehicles together. In the District of Columbia the Code lets your insurer put a term in the policy that precludes stacking, so your policy wording decides.

What stacking means

Many auto policies list a UM/UIM limit for each insured vehicle. Stacking adds those limits after one injury, so $100,000 on each of three vehicles becomes $300,000. Unstacked coverage pays only one limit. It matters only when your damages are larger than a single limit and larger than what the at-fault driver paid.

How the District treats it

D.C. Code 31-2406 says a motor vehicle policy may include terms and conditions that preclude stacking of uninsured motor vehicle coverages (subsection (f)(7)), and that insurance that includes underinsured motor vehicle coverage may include terms and conditions that preclude stacking of it (subsection (c-1)). The Code permits those terms; it does not itself say that stacking is allowed or banned.

A worked example

Suppose a household policy shows $100,000 of UM on each of three vehicles and an uninsured driver causes $250,000 of damages. If the policy has a clear anti-stacking term, the most it pays is $100,000. If it says nothing of the kind, each vehicle's coverage may apply and the ceiling would be $300,000, so you could reach the full $250,000. Try your own numbers in the District of Columbia UM/UIM stacking calculator.

What we could not confirm

We did not read District case law on whether courts enforce a given anti-stacking clause or an "other insurance" clause, or on separate policies. Ask your insurer to state its position in writing, and ask an attorney before assuming either result.

What to check

Look at your declarations page for the number of vehicles and the limit, and read the UM/UIM section for language that limits you to one coverage. See what the statute says and leaves open and how mandatory UM and optional UIM work.

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