TRICARE and DEERS. To be eligible and enroll in TRICARE, you must be registered in DEERS. Incorrect information in your DEERS record can cause problems with TRICARE claims as well as other health care benefits, so it’s critical you maintain the accuracy of DEERS records for you and your family.
: https://milconnect.dmdc.osd.mil/milconnect/public/faq/DEERS-TRICARE_and_DEERS

