By Christian BrinkleyLicensed NC Insurance Agent, NPN 22217190, NC Life & Health · Updated October 14, 2026 · 4 min read
More people are working past 65 than ever. If you are one of them, you face a choice about Medicare: enroll at 65 or delay? The answer depends on your employer coverage, your employer size, and whether you have a Health Savings Account. Get it wrong and you can face penalties, gaps in coverage, or lose HSA contributions. Get it right and you keep the coverage that fits best while avoiding extra costs.
Employer Coverage Basics
If you are still working at 65 with health coverage from a current job, you may be able to delay Medicare without a penalty. But rules differ for Part A and Part B, and employer size matters.
Part A While Still Working
Part A is hospital insurance. Most people get it premium free after 10 years of Medicare taxes. If you qualify for premium free Part A, enrolling at 65 usually makes sense even while working. It can act as secondary coverage at no premium cost.
Part B While Still Working
Part B is medical insurance with a monthly premium. With active employer coverage from a current job with 20 or more employees, you can usually delay Part B without a penalty. Many people do, to avoid paying for coverage they do not need yet.
With fewer than 20 employees, Medicare is usually primary even while you work. Enroll in Part B when first eligible. If you do not, your employer plan may pay as secondary, leaving you with bigger bills, plus a possible late penalty.
Who Pays First?
When you have both employer coverage and Medicare, one payer is primary. With 20 or more employees, the employer plan is primary and Medicare is secondary. With fewer than 20, Medicare is primary.
This matters. If Medicare is primary and you do not enroll, your employer plan may pay less than you expect because it assumes Medicare paid first. Confirm with your benefits office who is primary in your situation.
HSA Rules in Detail
This deserves attention because it is easy to get wrong. To contribute to an HSA, you must have a qualifying high deductible health plan and not be enrolled in Medicare.
If you are turning 65 with an HSA, talk to a tax professional and your benefits office before enrolling in Medicare.
Part D While Still Working
If your employer drug coverage is creditable, at least as good as standard Part D, you can delay Part D without a penalty. Your employer sends a yearly notice saying whether drug coverage is creditable. Keep it.
When employer coverage ends, you get a Special Enrollment Period, usually two months, to join Part D. Enroll promptly. A gap of 63 days or more without creditable drug coverage can trigger the Part D late penalty.
When You Retire: A Checklist
First, confirm the date your employer coverage ends, and whether COBRA or retiree coverage after that counts as creditable.
Second, enroll in Part A if you have not. If you delayed for HSA reasons, stop HSA contributions first, keeping the six month retroactive rule in mind.
Third, enroll in Part B during your Special Enrollment Period. Your employer must complete a form confirming your coverage dates.
Common Mistakes
Delaying Part B with a small employer is the most common. With fewer than 20 employees, Medicare is usually primary. Delaying can mean big bills plus a penalty.
Enrolling in Part A while contributing to an HSA is another. It ends contributions, and retroactive Part A can create excess contribution problems.
Assuming COBRA lets you delay Part B is a third. It generally does not.
Getting Help
Talk to your employer benefits office first. Ask about employer size, whether coverage is creditable, and when coverage ends. Your state SHIP program offers free, unbiased counseling. In North Carolina, it is called SHIIP. You can also call 1-800-MEDICARE or a local licensed insurance agent.
This article is general information only. It is not personal advice, tax advice, or a recommendation about any specific plan.
Questions people ask me about this
Who pays first?
When you have both employer coverage and Medicare, one payer is primary. With 20 or more employees, the employer plan is primary and Medicare is secondary. With fewer than 20, Medicare is primary. This matters.
What should I know about employer coverage basics?
If you are still working at 65 with health coverage from a current job, you may be able to delay Medicare without a penalty. But rules differ for Part A and Part B, and employer size matters. The key question is whether your coverage is creditable.
What should I know about medicare while working?
Part A is hospital insurance. Most people get it premium free after 10 years of Medicare taxes. If you qualify for premium free Part A, enrolling at 65 usually makes sense even while working. It can act as secondary coverage at no premium cost. One major exception: the HSA rule.
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