Tricare (often styled TRICARE) is the insurance product owned and operated by the US Department of Defense (DoD); it covers more than 9 million beneficiaries nationwide (Box).^1-3 Tricare claims data are maintained by the Military Health System Data Repository (MDR).^1-5 Research is performed using administrative insurance claims prepared by the MDR.

Tricare insurance is available to active duty service members, retirees, and individuals who are separated from service with certain disabilities, as well as their dependents.¹ At present, only 20% of the covered population consists of active military personnel, with the remaining 80% composed of civilians.^1-5 Eligible beneficiaries can maintain Tricare coverage through age 65 years, when transition to Medicare coverage typically occurs. The diverse sociodemographic, vocational, educational, and occupational characteristics of the population insured through Tricare has been found to be representative of the general American population up to age 64 years.^1,5,6 Tricare insurance is not used to cover services administered in combat zones or health care provided through the Veterans Administration (VA). Individuals with both VA benefits and Tricare may choose to receive some or all aspects of their care at VA hospitals.