Enrolling in Medicare

Do I have to enroll in Medicare at 65 if I'm still working?

Not always. If you have health coverage through an employer with 20 or more employees, you can usually delay Part B without penalty and enroll later through a Special Enrollment Period. With a smaller employer, Medicare often becomes your primary coverage, so enrolling at 65 is generally the safe move.

Reviewed by Scott Stafford, Licensed Insurance Agent

Last updated June 21, 2026

Most people take Part A at 65 because it's usually premium-free and doesn't hurt to have. The real question is Part B, which has a monthly premium — and the answer depends on your employer coverage.

Large employer (20+ employees)

If you or your spouse work for an employer with 20 or more employees and you have coverage through that job, that plan generally pays first and Medicare pays second. You can usually delay Part B without a penalty, then sign up later through a Special Enrollment Period that runs for eight months after the job or the coverage ends.

Small employer (fewer than 20)

With a smaller employer, Medicare usually becomes your primary coverage at 65, and the employer plan pays second. Because of that, you generally need to enroll in Part B at 65 — delaying could leave you with gaps and a late-enrollment penalty later.

Retiree coverage, COBRA, and marketplace plans do not count as active employer coverage for delaying Part B. If your only coverage is one of those, enrolling on time is usually important. A licensed agent can confirm your situation.

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