Is an entity that is acting as a third party administrator to a group health plan a covered entity?
No, providing services to or acting on behalf of a health plan does not transform a third party administrator (TPA) into a covered entity. Generally, a TPA of a group health plan would be acting as a business associate of the group health plan. Of course, the TPA may meet the definition of a covered entity based on its other activities (such as by providing group health insurance). See 45 CFR 160.103 (GPO).