Medicare and COBRA: Which Comes First? Avoiding Costly Mistakes

When you retire or lose employer health coverage, you may be offered COBRA continuation coverage -- the ability to keep your employer's health plan for up to 18 months by paying the full premium yourself. At the same time, you may be eligible for Medicare.

The question many retirees ask: Can I take COBRA instead of Medicare? Should I?

The answer is almost always: No -- and doing so can be a very expensive mistake.

Here's everything you need to know about Medicare and COBRA, and how to navigate this transition correctly.

COBRA (Consolidated Omnibus Budget Reconciliation Act) allows you to continue your employer-sponsored health insurance after leaving a job, for up to:

• 18 months if you lose coverage due to job loss or reduced hours
• 36 months in some other qualifying events (divorce, death of covered employee, etc.)

The catch: you pay the full premium -- both your share and your employer's share -- plus a 2% administrative fee. This can easily run $500-$1,500+ per month for an individual.

Here's the rule that trips up many retirees:

Once you are eligible for Medicare (age 65 or older), COBRA becomes secondary to Medicare -- not the other way around.

This means:

• COBRA will not pay claims that Medicare should have paid first
• If you delay Medicare enrollment and rely on COBRA, you may have significant uncovered costs
• COBRA does NOT count as "creditable coverage" that allows you to delay Medicare without penalty

This is where the real danger lies. If you delay enrolling in Medicare Part B because you have COBRA, you may face a permanent late enrollment penalty.

The Part B late enrollment penalty is 10% per year (or fraction of a year) that you delayed enrollment past your Initial Enrollment Period. This penalty is added to your Part B premium for life.

If you delay Part B enrollment for 2 years because you thought COBRA was sufficient:

• 2026 Part B premium: $202.90/month
• 20% penalty (2 years × 10%): +$40.58/month
• Your premium: $243.48/month -- forever

Over 20 years, that's nearly $10,000 in extra premiums.

Your Initial Enrollment Period (IEP) for Medicare is a 7-month window:

• 3 months before the month you turn 65
• The month you turn 65
• 3 months after the month you turn 65

If you don't enroll during your IEP, you must wait for the General Enrollment Period (January 1 - March 31 each year), with coverage starting July 1 -- and you'll owe the late enrollment penalty.

There IS a legitimate reason to delay Medicare: if you or your spouse is still actively working and covered by a current employer's group health plan (not COBRA -- actual active employment).

In this case, you have a Special Enrollment Period that allows you to enroll in Medicare without penalty when that active coverage ends.

COBRA is not active employer coverage. It's continuation coverage after employment ends. The IRS and CMS are clear: COBRA does not qualify for the active coverage exception.

Here's what you should do when you retire or lose employer coverage:

Enroll during your Initial Enrollment Period (or Special Enrollment Period if you had active employer coverage). Part A is usually free; Part B costs $202.90/month in 2026.

Once you have Medicare, you can evaluate whether to:

• Add a Medicare Supplement (Medigap) plan for comprehensive coverage
• Enroll in a Medicare Advantage plan as an alternative to Original Medicare
• Potentially use COBRA as a short-term bridge for dental/vision/prescription coverage not yet covered by Medicare

COBRA can make sense as a short-term supplement if:

• You need dental or vision coverage while you find a Medicare Advantage plan with those benefits
• You have a specific prescription that isn't covered under Medicare Part D yet
• You're in the middle of a treatment and want continuity with your current providers

But COBRA should never replace Medicare as your primary coverage.

If you delay Part D enrollment because you have COBRA drug coverage, you may also face a Part D late enrollment penalty -- 1% of the national base beneficiary premium per month of delay.

COBRA drug coverage may or may not be "creditable" (as good as Medicare Part D). Your employer is required to notify you whether your coverage is creditable. If it's not creditable, you should enroll in Part D immediately.

If you're already on COBRA when you turn 65, your Initial Enrollment Period begins as normal. You must enroll in Medicare Parts A and B during your IEP to avoid penalties.

If your spouse is still actively employed and you're covered under their employer plan, you can delay Medicare without penalty. But once your spouse retires or loses that coverage, you have an 8-month Special Enrollment Period to enroll in Medicare.

Some employers offer retiree health benefits (not COBRA -- actual retiree coverage). These may or may not be creditable for Medicare purposes. Always verify with your HR department and a Medicare specialist.

The Medicare-COBRA interaction is one of the most misunderstood areas of Medicare enrollment. The key takeaways:

1. COBRA does not delay your Medicare enrollment obligation
2. Delaying Medicare while on COBRA can result in permanent penalties
3. Enroll in Medicare Parts A and B during your Initial Enrollment Period
4. Use COBRA only as a supplement, not a replacement, for Medicare

If you're approaching retirement and unsure how to coordinate your Medicare enrollment with COBRA or other coverage, I can walk you through the exact steps. Call me at (386) 871-3858 or schedule a free consultation at calendly.com/themedicaredude/75.

William Gray is an independent Medicare specialist licensed in Florida (License #W690237). He represents 60+ carriers and helps Florida seniors find the right coverage for their individual needs.