Working Past 65: Do You Have to Sign Up for Medicare?
If you keep working past 65 and have health coverage through an employer with 20 or more employees, you can usually delay Part B without a late penalty and enroll later through a Special Enrollment Period. Many people still take premium-free Part A. One key exception: if you contribute to a Health Savings Account (HSA), you must stop HSA contributions once you enroll in any part of Medicare.
Employer size is what matters
If your (or your spouse’s) employer has 20 or more employees, that group plan is generally the primary payer and you can delay Part B penalty-free while it is active. If the employer has fewer than 20 employees, Medicare usually becomes the primary payer at 65, so you typically should enroll in Part B on time.
Should you take Part A?
Most people take premium-free Part A at 65 even while working, because it has no premium. The exception is if you contribute to an HSA — enrolling in Part A (or any Medicare) means you must stop HSA contributions to avoid tax penalties.
Enrolling when you stop working
When your employer coverage ends, you get an 8-month Special Enrollment Period to sign up for Part B without penalty. Do not rely on COBRA or retiree coverage to delay — those generally do NOT count as qualifying coverage for avoiding the Part B penalty.
Frequently asked questions
Does COBRA count as coverage to delay Part B?
No. COBRA and retiree coverage generally do not let you delay Part B penalty-free. Enroll in Part B when your active employment coverage ends to avoid a penalty.
Can I keep my HSA on Medicare?
You can keep and spend an existing HSA, but you cannot make new contributions once you enroll in any part of Medicare. Plan the timing carefully if you contribute to an HSA.
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Medicare Login Guide is an independent resource and is not affiliated with or endorsed by Medicare, the Centers for Medicare & Medicaid Services, or any government agency. This article is for general information only — confirm current figures and your specific options at medicare.gov or by calling 1-800-MEDICARE.