Original Medicare:
Medicare as a Secondary Payer

Medicare as a Secondary Payer and Employer Group Health Plans

Medicare payment will be secondary or excluded when the following types of insurance are available to cover health care costs:

• Workers’ compensation
• Automobile, no-fault, or liability insurance
• Employer group health plans

Individuals aged 65 and older
When a beneficiary aged 65 or older has employer group health coverage based upon active employment or the current employment of a spouse by an employer with 20 or more employees, the beneficiary may choose Medicare or the employer-based plan as the primary insurer.

Individuals under age 65
Medicare is the secondary payer for beneficiaries who are entitled to Medicare based on disability and are covered by a large group health plan (LGHP) through their active employment or that of a family member. An LGHP is sponsored by an employer who normally employs at least 100 full- or part-time employees on at least 50 percent of the regular business days in the preceding calendar year.

Special Enrollment Period
Medicare beneficiaries who are actively working, or are covered by a spouse’s active employment policy, are entitled to a special enrollment period (SEP) if they opt for coverage under an employer’s plan rather than Medicare.

See, 42 C.F.R § 411, et. seq.

HAP Resources 

Chart: Medicare Secondary Payer Rules