Who qualifies for Medicare, and exactly when.
Turning 65 is the most common door into Medicare, but it is not the only one. Here is every eligibility path, what it costs, and the traps that catch people who assume they already know.
The four doors into Medicare
| Who | When |
|---|---|
| Age 65 | 7 months starting 3 months before your 65th birthday month |
| Disability (SSDI) | After 24 months of receiving Social Security Disability Insurance |
| ALS (Lou Gehrig's disease) | Immediately upon SSDI approval — no 24-month wait |
| ESRD (kidney failure) | Immediately upon dialysis or transplant, with some timing rules |
Work history sets the Part A price
Your Part A premium depends on how many quarters you (or your spouse) worked under Medicare-tax-paying employment. If you or your spouse worked 40 or more quarters (roughly 10 years), your Part A premium is $0. If you worked fewer than 40 quarters, you may pay up to $565 per month.
Still working at 65: the 20-employee rule
If you have group health coverage through an employer with 20 or more employees, you can safely delay Part B without penalty. Medicare will be secondary, and your employer plan is primary.
If your employer has fewer than 20 employees, Medicare is primary from day one. You should enroll in both Parts A and B during your IEP. If you do not, you risk a lifetime penalty and gaps in coverage.
COBRA Warning: COBRA is not creditable coverage for Medicare. If you are on COBRA and turn 65, you must enroll in Medicare during your IEP. Staying on COBRA as your only coverage triggers lifetime Part B penalties and gaps that cannot be undone.
Your 90-second eligibility self-check
- Am I 65 or approaching 65? If yes, your IEP is the 7 months around your birthday. Mark it.
- Do I have 40+ quarters of work (or does my spouse)? If yes, Part A is $0. If not, budget for a premium.
- Am I still working with employer coverage? If yes, how many employees does the employer have? 20+ means you can delay Part B. Fewer than 20 means enroll now.
- Do I have COBRA or retiree coverage? These are not substitutes for Medicare. Enroll in Medicare first.
- Do I have a disability, ALS, or ESRD? You may qualify earlier than 65. Contact Social Security to confirm your start date.
Professor's Note: The COBRA trap is the most expensive mistake we see. People think COBRA means they are covered, so they skip Medicare enrollment. Then they discover the lifetime penalty and the coverage gap — and there is no appeal, no exception, no undo button. If you or someone you know is on COBRA and approaching 65, call us before the deadline passes.
Questions from this lesson
Can I get Medicare before 65?
Yes. If you have been receiving Social Security Disability Insurance (SSDI) for 24 months, you automatically qualify for Medicare. You also qualify immediately if you have been diagnosed with ALS or End-Stage Renal Disease (ESRD).
What if I am still working at 65?
If your employer has 20 or more employees, you can delay Part B without penalty. If the employer has fewer than 20 employees, you should enroll in Medicare as primary. Always coordinate with your employer benefits department.
Does my spouse's work history affect my Medicare?
If you are at least 65, married, and your spouse has worked 40+ quarters under Medicare-tax-paying employment, you can qualify for premium-free Part A based on their record — even if you never worked.
What happens to COBRA when I turn 65?
COBRA does not end at 65, but it should not be your primary coverage. Medicare becomes primary when you turn 65. Staying on COBRA as your only coverage can result in lifetime Part B penalties and gaps. Enroll in Medicare first, then COBRA can serve as supplemental coverage if needed.
Graduate: book your free review
You now know more about Medicare than most people. The next step is turning that knowledge into the right plan for your situation. Book a free, no-pressure review and we will compare every option side by side.