Still Working at 65? Here's What You Need to Know About Medicare
Working past 65 is more common than ever — but Medicare's rules for people with employer coverage are full of traps. One wrong move can mean permanent premium penalties or a gap in coverage.
The Good News — and the Catch
If you're still working at 65 and have employer health coverage through active employment, you generally can delay Medicare enrollment without penalty. That's the good news. The catch: the rules are specific, the exceptions are numerous, and the consequences of getting it wrong are permanent. This page walks you through everything you need to know.
Key rule: The employer coverage must be through YOUR active employment or a current spouse's active employment. Retiree coverage, COBRA, and marketplace plans do NOT qualify for delayed enrollment.
Your Situation Determines Your Strategy
You work for a company with 20+ employees
Good NewsYour employer plan is primary. You can delay both Part A and Part B without penalty. You'll have an 8-month Special Enrollment Period after your employment or coverage ends — whichever comes first — to enroll in Part B without penalty.
Delay Medicare. Enroll during your SEP when coverage ends.
You work for a company with fewer than 20 employees
Act NowMedicare becomes primary even if you have employer coverage. Your employer plan pays secondary. You should enroll in Medicare Parts A and B at 65 to avoid gaps and penalties — your employer plan alone may leave you significantly underinsured.
Enroll in Medicare at 65. Do not delay.
You're covered under a spouse's employer plan
Review CarefullyIf your spouse is actively employed and their employer has 20+ employees, you can delay Medicare without penalty. If the employer has fewer than 20 employees, Medicare becomes primary and you should enroll at 65.
Check employer size. Delay if 20+ employees; enroll at 65 if fewer.
You have COBRA or retiree coverage
Act NowCOBRA and retiree coverage do NOT qualify as employer coverage for Medicare delay purposes. If you're relying on COBRA or retiree coverage at 65, you must enroll in Medicare during your Initial Enrollment Period to avoid permanent late penalties.
Enroll in Medicare at 65. COBRA and retiree coverage do not protect you.
You have a Health Savings Account (HSA)
Review CarefullyOnce you enroll in any part of Medicare, you can no longer contribute to an HSA. If you want to keep contributing, delay Medicare enrollment. However, you must stop contributions at least 6 months before enrolling in Part A (which can be backdated up to 6 months).
Stop HSA contributions 6 months before Medicare enrollment to avoid tax penalties.
Your Special Enrollment Period (SEP)
When your employer coverage ends — whether because you retire, lose your job, or your employer stops offering coverage — you have an 8-month Special Enrollment Period to enroll in Medicare Part B without a late penalty. This window starts the month after your employment or coverage ends, whichever comes first.
The SEP is 8 months — not 60 days. But don't wait too long. If you need a Medicare Supplement plan, you have guaranteed issue rights for only 6 months after Part B starts.
COBRA does NOT extend your SEP. Your 8-month window starts when your employer coverage ends, not when COBRA ends.
You cannot use the marketplace or COBRA to bridge a gap and then enroll in Medicare later without penalty.
Part A enrollment can be backdated up to 6 months. If you're enrolling in Part A late, watch out for HSA contribution conflicts.
The Penalties for Getting It Wrong
Part B late enrollment penalty
10% added to your Part B premium for each full 12-month period you were eligible but didn't enroll. This penalty is permanent — it lasts as long as you have Part B.
Part D late enrollment penalty
1% of the national base beneficiary premium for each month you went without creditable drug coverage. Also permanent.
Loss of Medigap guaranteed issue rights
You have a 6-month guaranteed issue window for Medicare Supplement plans starting when Part B begins. Miss this window and insurers can medically underwrite — or deny — your application.
4 Steps to Take Before You Retire
Confirm your employer's size
Ask HR whether your employer has 20 or more employees. This single fact determines whether Medicare is primary or secondary — and whether you can safely delay enrollment.
Get a creditable coverage letter
When your employer coverage ends, get a letter from your employer confirming your coverage was creditable. You'll need this to prove you had qualifying coverage and avoid late penalties.
Plan your HSA contributions
If you have an HSA, stop contributions at least 6 months before you plan to enroll in Medicare to avoid IRS penalties on excess contributions.
Call me before you retire
The best time to plan your Medicare transition is 3–6 months before your retirement date. I'll walk you through your specific situation, your enrollment window, and your plan options — at no cost to you.
Frequently Asked Questions
Still Working at 65? Let's Make Sure You're Protected.
The rules for working past 65 are complicated — and the penalties for getting them wrong are permanent. I help Northeast Florida residents navigate this transition correctly, at no cost to you.