Forced to predict how the Pennsylvania Supreme Court would decide an important question of auto insurance law, a federal judge has ruled that a new stacking waiver is required when a car owner cancels the underinsured motorist coverage on her auto insurance policy and later decides to add the UIM coverage back onto the policy.

In his 13-page opinion in Nationwide Mutual Insurance Co. v. Zerr , U.S. District Judge Berle M. Schiller concluded that Robin Zerr’s decision to add the UIM coverage back onto the policy was a “purchase” that triggered the insurer’s duty to secure a new stacking waiver.