UMR offers flexible, third-party administration of multiple, complex plan designs. FIND A PROVIDER | UnitedHealthcare Options PPO Network. UMR, UnitedHealthcare's TPA solution, is the nation's largest third-party. United Medical Resources, subsidiary and third party administrator for United Healthcare Services Incorporated, a medical insurance provider. UMR is PEIA's third-party administrator that handles medical claim processing, case. UMR aims to deliver, on a seamless basis, value-added services such as national health care provider network discounts, advanced.