The Supreme Court of Pennsylvania has ruled that a waiver signed by an insured did not waive the right to aggregate or "stack" the limits of coverage for underinsured benefits between two separate policies of insurance. The case is Donovan v. State Farm Mut. Auto. Ins. Co., 256 A.3d 1145 (Pa. 2021).

After Corey Donovan was involved in an accident while riding his motorcycle, the insurer for the motorist who allegedly struck Donovan tendered the full liability limit of $25,000 available under the motorist's policy.

Donovan then filed a claim for UIM benefits under the motorcycle policy he held with State Farm Mutual Automobile Insurance Company. The policy provided UIM coverage up to $50,000 per person, and State Farm tendered the full limit available under the policy.