As defined by the California Code of Regulations, a person who asserts a right of recovery under an insurance policy is called the

A beneficiary is a person or entity designated to receive benefits from an insurance policy, typically upon the death of the insured. While beneficiaries may benefit from claims, they do not actively assert a right of recovery; instead, they receive the proceeds as outlined in the policy.

The term "injured" refers to someone who has suffered harm or damage, which may or may not be related to an insurance claim. Being injured does not automatically mean that an individual is making a claim under an insurance policy; therefore, it does not accurately describe the person asserting a right of recovery.

An underinsured individual has insufficient insurance coverage to fully protect against a loss. This term describes a person's insurance status rather than their role in the claims process. An underinsured person may still be a claimant, but the term does not define someone asserting a right of recovery.