TRICARE (formerly known as CHAMPUS) is the Department of Defense's health care program for retired members of the uniformed services, as well as the spouses and children of active duty, retired and deceased service members. TRICARE is considered a group health plan for SEP and premium surcharge rollback purposes. However, these provisions apply only to beneficiaries whose coverage under TRICARE is based on active duty military status. These individuals can enroll (or reenroll) in SMI during any month while they are covered under TRICARE or during the 8-month period that begins the month following the last month that TRICARE coverage was based on active duty military status.

If however, Susan's coverage under TRICARE is based on her husband's past military service (which is generally the case for the aged), she is not eligible for an SEP or the premium surcharge rollback.

The Form HCFA-L564 will not be used to obtain evidence of coverage under TRICARE. Instead, the Department of Defense (DoD), will issue a letter verifying the beneficiary's eligibility for TRICARE benefits. The letter will also provide the dates of coverage.

Beneficiaries requesting an SEP who do not have the DoD notice should be directed to contact the DoD's Defense Enrollment Eligibility Reporting System (DEERS) at one of the following numbers to obtain proof of coverage under TRICARE.