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COBRA vs. Medicare After Age 65: Which Coverage Comes First?
Last Modified: 10/05/2026 | Reviewed by Keith Armbrecht (NPN 634015)
Quick Summary
If you’re 65 or older and leave a job with employer health insurance, choosing COBRA doesn’t generally allow you to postpone Medicare Part B enrollment until COBRA ends without consequences.
Your Medicare Part B Special Enrollment Period generally lasts up to 8 months after you stop working or lose qualifying job-based coverage, whichever occurs first—even if you choose COBRA.
Waiting until 18 months of COBRA ends could potentially cause a Medicare coverage gap and Part B late enrollment penalty.
Key Facts
- COBRA isn’t the same as active-employer coverage for Medicare enrollment purposes.
- You can have COBRA and Medicare in certain circumstances.
- Your Part B SEP doesn’t extend simply because you choose COBRA.
- The common employer-based Part B SEP lasts up to 8 months.
- The clock starts when employment or qualifying job-based coverage ends, whichever occurs first.
- Missing the SEP can cause a coverage gap.
- A lifetime Part B late enrollment penalty may apply.
- Medicare may pay before COBRA after employment ends.
- Drug coverage requires separate attention.
- Medigap enrollment timing also matters.
The Mistake to Avoid
Suppose you retire at age 67 and elect:
18 months of COBRA
You assume:
“I’ll enroll in Part B when COBRA ends.”
That’s potentially a serious mistake.
Your Part B Special Enrollment Period generally doesn’t wait for your COBRA coverage to expire.
A Simple Timeline
June 30: You retire and active employer coverage ends.
July 1: COBRA begins.
Your Part B Special Enrollment Period generally begins when the active employment or job-based coverage ends.
It doesn’t begin 18 months later when COBRA expires.
What Could Happen If You Wait?
If you miss your Medicare enrollment opportunity, you may have to wait for the Medicare General Enrollment Period.
You could also face:
A gap in healthcare coverage
and potentially:
A Part B late enrollment penalty.
Should You Take COBRA at All?
COBRA can still be useful in some situations.
For example, it might provide continued coverage for a younger spouse or dependents.
But for the Medicare-eligible person, you need to understand how COBRA coordinates with Medicare before making the decision.
Video Explanation from Keith
COBRA or Medicare After 65?
Keith's Take
This is one Medicare mistake I really want people to avoid.
Someone retires after 65 and HR says:
“You can keep your insurance through COBRA.”
They hear that and think:
“Great. I don’t need Medicare yet.”
That’s not necessarily true.
COBRA can be excellent for a spouse or dependent, but it doesn’t stop your Medicare Part B enrollment clock the way active-employer coverage can.
Before retiring, coordinate Medicare first.
Keith Armbrecht
Medicare on Video
Frequently Asked Questions About COBRA and Medicare
Q. Can I choose COBRA instead of Medicare after 65?
A. You may be able to elect COBRA, but COBRA doesn't generally allow you to delay Part B indefinitely without enrollment consequences.
Q. How long is the Part B SEP?
A. Generally up to 8 months after current employment or qualifying employer coverage ends.
Q. Does the 8-month period begin when COBRA ends?
A. No.
Q. Can I have Medicare and COBRA?
A. Yes, in certain circumstances
Q. Which pays first?
A. After active employment ends, Medicare is generally primary to COBRA for Medicare-eligible individuals, subject to applicable coordination rules.
Q. Can COBRA cover my younger spouse?
A. Potentially. This is one reason COBRA may still be valuable for a family.
Q. What if I wait until COBRA expires?
A. You could miss your Part B SEP and potentially face a coverage gap and penalty.
Official Government Sources
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