A policy rider is an addition or amendment to an existing insurance policy that provides extra coverage or benefits. It allows policyholders to customize their insurance to better meet their specific needs. For example, someone with a life insurance policy might add a rider for accidental death benefits, which would pay out more if the insured dies in an accident. Riders can also come with additional costs, so it's important to understand the terms before adding one. Common types of riders include waiver of premium, critical illness, and disability income riders, each designed to enhance the protection offered by the base policy.