Does Massachusetts Allow UM/UIM Stacking? What Section 113L Says

By the FigureMyTax Editorial Team · How we calculate

No. Massachusetts statute says the limits of two or more vehicles or policies may not be added, combined or stacked, and it picks the single policy that applies.

The antistacking rule

Paragraph (5) of section 113L says uninsured motorists coverage shall provide that regardless of the number of vehicles involved, whether insured or not, persons covered, claims made, premiums paid or the number of premiums shown on the policy, in no event shall the limit of liability for two or more vehicles or two or more policies be added together, combined or stacked to determine the limits of insurance coverage available to injured persons.

Which single policy

A named insured injured in a non-owned registered vehicle recovers only from the policy with the highest limits on which he or she is a named insured, pro rata if several have equal limits. A named insured injured in an owned registered vehicle that had the required coverage recovers only from the policy covering that vehicle. An insured who is not a named insured may recover only from a resident relative's policy with the highest limits. Occupants who are not insured on a resident relative's policy may use the policy covering the vehicle they occupy. A named insured in an owned vehicle without the compulsory coverage may not recover UM from any policy.

The underinsured rule

Paragraph (2) makes an insured vehicle count as uninsured, if you elect to buy the coverage, when its bodily injury limit is less than your coverage and insufficient to satisfy your damages, and only to the extent your coverage limits exceed the at-fault limit. The statute's paragraph (3) separately limits an "extension of coverage" to accidents where the tortfeasor's insurer has been declared insolvent. We did not read the court decisions that reconcile paragraphs (2) and (3), so confirm with an attorney how your policy applies underinsured coverage.

Protection of your recovery

After paying you, the insurer is entitled to the proceeds of your recovery against the responsible party only once you have received full compensation for your injuries (paragraph (4)).

How to use this

Compare the results in the Massachusetts UM/UIM stacking calculator, start with the plain-English stacked versus single-policy explainer, and read how Massachusetts UM and UIM work.

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