Active-duty service members are automatically registered in the Defense Enrollment Eligibility Reporting System (DEERS). Family members, however, must personally ensure they are enrolled in DEERS to be eligible for Tricare benefits. Failure to keep DEERS information current can cost extra time in the waiting room or expensive out-of-pocket expenses, warn Tricare officials. To learn which documents are needed to register or update DEERS information, sponsors and their families should contact the nearest uniformed services identification card facility. To find one, search by ZIP Code at dmdc.osd.mil. Beneficiaries may update information on DEERS in one of the following ways: visit a local uniformed services ID card facility; call the Defense Manpower Data Center Support Office at 1-800-538-9552; fax changes to DEERS at 1-831-655-8317; mail the address change to the Defense Manpower Data Center Office, ATTN: COA, 400 Gigling Road, Seaside, Calif. 93955-6771; or update addresses electronically at tricare.osd.mil/DEERS.