COBRA and Medicare Guide
COBRA and Medicare: Do I Need Part B at 65?
COBRA can continue an employer health plan after employment ends, but it is not treated as coverage based on current employment for Medicare Part B enrollment.
The most important issue is timing: choosing COBRA does not restart or extend your limited opportunity to enroll in Part B without a late penalty.
Mike Surrano
Your local insurance coach
The quick answer
COBRA Does Not Protect Your Part B Enrollment Rights the Same Way Active Employer Coverage Can
If you are turning 65 while already on COBRA, you generally should not assume that COBRA lets you delay Part B. If employment or active employer coverage recently ended, your Part B Special Enrollment Period may already be running.
Which situation are you in?
Common COBRA and Medicare Scenarios
You Are Turning 65 While Already on COBRA
COBRA is not current-employment coverage for Part B enrollment purposes. Use your Medicare Initial Enrollment Period unless another valid enrollment right applies.
You Left Work After 65 and Chose COBRA
Your 8-month Part B Special Enrollment Period generally starts when the employment or active employer coverage ends, whichever happens first. COBRA does not pause it.
You Had Medicare Before Electing COBRA
You may be able to elect COBRA, but Medicare generally pays first and COBRA pays second. Confirm how the plan coordinates benefits before paying the COBRA premium.
You Had COBRA Before Enrolling in Medicare
Your COBRA coverage may end when Medicare begins. Ask the COBRA administrator what happens to your coverage and to coverage for your spouse or dependents.
Your COBRA Includes Prescription Coverage
The drug coverage may be creditable for Part D even though COBRA does not count as current-employment coverage for the Part B Special Enrollment Period.
Your Spouse or Children Also Have COBRA
Family members may have separate COBRA continuation rights. The employee’s Medicare enrollment does not always mean every dependent loses coverage at the same time.
The Part B deadline
How the 8-Month Special Enrollment Period Works
Coverage based on your or your spouse’s current employment may allow Part B to be delayed. After the employment or active group coverage ends, a limited Special Enrollment Period may be available.
Do not count eight months from the end of COBRA
The Part B Special Enrollment Period generally ends eight months after the employment or active group health coverage ends, whichever happens first. Taking COBRA does not change that ending date.
Employment or Active Coverage Ends
Identify the last day of current employment and the last day of active employer group health coverage.
The Part B SEP Begins
The 8-month window generally starts after employment or active coverage ends, whichever happens first.
COBRA May Continue
You may elect COBRA, but it does not stop, restart, or extend the Part B enrollment window.
Part B Must Be Timed Correctly
Apply before the SEP expires and coordinate the effective date to avoid a gap between COBRA and Medicare.
Who pays first?
How Medicare and COBRA May Coordinate
When a person has both Medicare and COBRA, Medicare generally pays first and COBRA pays second, except in certain situations such as the Medicare coordination period for End-Stage Renal Disease.
When Medicare Pays First
- Give both insurance cards to doctors, hospitals, and pharmacies.
- Providers generally submit the claim to Medicare first.
- The COBRA plan may then process some remaining eligible costs according to its rules.
- COBRA is not automatically a substitute for enrolling in Part B.
Questions to Ask the COBRA Administrator
- Will my COBRA end when Medicare becomes effective?
- Will the plan pay anything if I delay Part B?
- How does the plan coordinate with Parts A and B?
- Can my spouse or dependents continue COBRA separately?
- Is the prescription coverage creditable for Part D?
Part D is different
COBRA Prescription Coverage May Be Creditable
Part B and Part D use different rules. A COBRA medical plan does not extend the Part B SEP, but the prescription portion may allow you to delay Part D if the plan confirms in writing that the drug coverage is creditable.
Keep the Creditable Coverage Notice
The plan should tell you whether its prescription coverage is expected to pay, on average, at least as much as standard Medicare drug coverage. Keep the written notice for your records.
Avoid a 63-Day Gap
Going 63 days or more without Medicare drug coverage or other creditable prescription coverage may result in a Part D late enrollment penalty.
Prescription lists, pharmacies, premiums, deductibles, and annual costs should be compared before your COBRA drug coverage ends.
Read the Medicare Part D GuideBefore choosing COBRA
Complete This Medicare Timing Checklist
Confirm Your Dates
Write down your 65th birthday month, employment end date, active health coverage end date, COBRA start date, and desired Medicare start date.
Verify the Type of Coverage
Ask whether the plan is based on current employment, COBRA, retiree coverage, or another arrangement. The label changes the Medicare enrollment rules.
Review HSA Contributions
If you have an HSA, Medicare Part A timing and possible retroactive coverage may affect when contributions must stop.
Check Prescription Coverage
Get the written creditable coverage notice and keep it. Do not assume every COBRA drug plan is creditable.
Compare Total Costs
Compare the full COBRA premium with Medicare premiums, drug coverage, and either Medicare Supplement or Medicare Advantage costs.
Coordinate Every Effective Date
Avoid ending COBRA before Medicare and any supplemental or drug coverage are confirmed to begin.
Still working, covered through a working spouse, or planning retirement? Employer size, HSA timing, and prescription coverage may also affect your enrollment decision.
Read the Working Past 65 GuideContributing to an HSA? Medicare Part A may begin retroactively when you enroll after 65, which can affect contribution eligibility.
Read the HSA and Medicare GuideForms and official guidance
Where to Verify the Rules and Apply
Medicare.gov: COBRA Coverage →
Official Medicare guidance on COBRA, the Part B deadline, and coordination.
Medicare.gov: When Can I Sign Up? →
Official enrollment periods, effective dates, and Special Enrollment Period information.
Social Security: Working and Part B →
Guidance on delaying Part B with qualifying current-employment coverage.
CMS-40B: Part B Application →
The application used to enroll in Medicare Part B.
CMS-L564: Employment Information →
Employer verification commonly used for a Part B Special Enrollment Period.
Medicare.gov: Who Pays First? →
Official coordination-of-benefits guidance for Medicare and other insurance.
Medicare.gov: Creditable Drug Coverage →
Part D creditable coverage and late-enrollment information.
U.S. Department of Labor: COBRA Guide →
Official information about COBRA election, duration, and beneficiary rights.
Frequently asked questions
COBRA and Medicare FAQs
Does COBRA let me delay Medicare Part B?
COBRA is not considered coverage based on current employment for the Part B Special Enrollment Period. If active employment or employer coverage ended, your limited Part B enrollment window may already be running.
When does the 8-month Part B Special Enrollment Period begin?
It generally begins after the employment or active group health plan coverage ends, whichever occurs first. Choosing COBRA does not extend the end of that period.
Will COBRA end when I enroll in Medicare?
If COBRA began before Medicare, the COBRA plan may end your coverage when you become entitled to Medicare. The outcome can differ for spouses and dependents, so confirm the plan’s rules before enrolling.
If I have both Medicare and COBRA, which pays first?
Medicare generally pays first and COBRA pays second. Different coordination rules may apply in limited situations, including the Medicare coordination period for End-Stage Renal Disease.
Can COBRA prescription coverage let me delay Part D?
Possibly. The plan must confirm that the prescription coverage is creditable. Keep the written notice and avoid going 63 days or more without Medicare drug coverage or other creditable drug coverage.
What happens if I miss the Part B Special Enrollment Period?
You may have to wait for the General Enrollment Period from January 1 through March 31, with coverage generally starting the month after enrollment. A lifetime Part B late enrollment penalty may also apply.
When does Medigap Open Enrollment begin?
For someone age 65 or older, the one-time six-month Medigap Open Enrollment Period starts the first month Medicare Part B is active. This timing is separate from the COBRA deadline.
About the author
Mike Surrano
Mike is an independent insurance agent with 14 years of insurance-industry experience. He helps people in Celina, Prosper, Frisco, McKinney, and surrounding North Texas communities understand Medicare enrollment timing and coverage choices.
Last reviewed: August 2026
Do not wait for COBRA to expire
Review Your Medicare Deadline Before Making a Coverage Decision
A short timing review can help identify your Part B deadline, coordinate effective dates, and prevent an avoidable coverage gap.
This page provides general educational information and is not legal or tax advice. COBRA rights, Medicare enrollment eligibility, coordination of benefits, and effective dates depend on individual circumstances and plan rules. Confirm your dates with Social Security, Medicare, and the COBRA or employer plan administrator.
We do not offer every plan available in your area. Currently, we represent a limited number of organizations that offer a limited number of products in your area. Please contact Medicare.gov, 1-800-MEDICARE, or your local State Health Insurance Assistance Program to get information on all of your options.
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