DEERS stands for Defense Enrollment Eligibility Reporting System, which is a computerized database of military sponsors, families, and others worldwide who are entitled to TRICARE and other benefits. Active-duty and retired service members are automatically registered in DEERS, but they must take action to register their family members and ensure they are correctly entered into the database. Once registered in DEERS, it is important to keep your DEERS records updated when personal eligibility information changes, such as addresses and family status (marriage, divorce, birth, adoption, etc.) . Mistakes in the DEERS database can cause problems with TRICARE claims, so it is critical to maintain your DEERS information. To update your information in DEERS, you can visit your personnel office, contact the Defense Manpower Data Center Support Office, or go online to the Milconnect website or Tricare website.