The four doors into Medicare
| Door | Who it covers | When coverage can start |
|---|---|---|
| Age 65 | U.S. citizens and legal residents (5+ years residency) | Your 65th birthday month, via the 7-month IEP |
| Disability | Anyone receiving SSDI for 24 months | Automatically in month 25 |
| ALS | People with amyotrophic lateral sclerosis | With the first month of disability benefits, no wait |
| ESRD | People with end-stage renal disease | Tied to dialysis start or transplant, special rules |
Work history sets the Part A price, not eligibility
You qualify for Medicare at 65 regardless of work history; what your 40 quarters buy is premium-free Part A. With 30 to 39 quarters, Part A costs $311 per month in 2026; below 30 quarters, $565. Spousal records count, which regularly rescues clients who spent careers raising families instead of filing W-2s.
Still working at 65: the 20-employee rule
If you or your spouse are actively employed and covered by a group plan from an employer with 20 or more employees, that plan stays primary and you may delay Part B without penalty, then use an 8-month Special Enrollment Period when the job or coverage ends. Under 20 employees, Medicare is primary whether you enroll or not, and skipping Part B can leave you effectively uninsured. Two warnings that save people real money:
- COBRA and retiree plans are not active employment. They do not delay the Part B clock.
- HSA contributions must stop before Medicare starts, and Part A can backdate up to six months, so time your final contributions carefully.
Your 90-second eligibility self-check
- Am I 65, or within the 7-month window around my 65th birthday?
- If younger: have I received SSDI for 24 months, or do ALS/ESRD rules apply?
- Do I (or my spouse) have 40 quarters of covered work?
- Is anyone in the household still actively employed with group coverage, and is that employer over or under 20 employees?
- Could my income qualify me for a Medicare Savings Program or Extra Help?
Your answers to those five questions determine your dates, your prices and your smartest first move. Which happens to be exactly what a free call with Jason maps out.
The costliest eligibility mistake we see is quiet: someone retires at 66, takes COBRA, and assumes the 8-month Part B window starts when COBRA ends. It started when they left the job. Set your dates from employment, not from whatever coverage came after it.