What is waiver of subrogation and why is it required?

A waiver of subrogation is an endorsement where your insurance carrier agrees not to pursue recovery (subrogate) against a specified party after paying a claim. In the MSA context, the turf vendor or tower owner requires you to add a waiver of subrogation in their favor on your GL, WC, and auto policies. This means that if your carrier pays a claim and determines the tower owner was partially at fault, the carrier cannot sue the tower owner to recover its payout. Without the waiver, the additional insured faces the risk of being sued by your own carrier after a loss, which defeats the purpose of being named as additional insured. Waivers must be in place before the loss occurs to be valid. Most carriers allow blanket waiver of subrogation endorsements that apply to any party required by written contract, similar to blanket additional insured. The cost is typically 2-5% of premium. For workers compensation, the waiver is particularly important because WC claims on tower sites often involve shared fault between the employer and the site owner. Without a WC waiver of subrogation, your WC carrier could pursue the tower owner for contribution, creating litigation that undermines the contractual relationship.