Do You Have To Sign Up For Medicare At 65?

Quick Answer
Not always, but the default answer is yes. Enrolling during the 7-month Initial Enrollment Period avoids a lifetime Part B penalty. The main exception is qualifying employer coverage from active employment at a company with 20 or more employees.
Nobody goes to jail for skipping Medicare. But the government designed the incentives so that skipping it without a qualifying reason costs money every month for the rest of a life — which makes the practical answer closer to yes than the legal one.
Who has to act at 65, and who doesn’t?
People already drawing Social Security are enrolled in Parts A and B automatically — the card arrives in the mail. Everyone else must sign up through Social Security, and no reminder comes. The window is the 7-month Initial Enrollment Period laid out in the turning-65 Medicare checklist: 3 months before the birthday month, the birthday month, and 3 months after.
What happens if someone just doesn’t enroll?
A permanent penalty starts accruing. Part B premiums rise 10% for every full 12-month period of delay without qualifying coverage, and that surcharge never expires. Delay three years and every Part B premium for life costs 30% more. Part D drug coverage carries its own smaller permanent penalty that builds monthly. The order of consequences:
- Coverage gap — no Medicare protection during the delay.
- Waiting for a general enrollment window to get back in.
- The lifetime Part B penalty stacked on every future premium.
Who can legitimately say no at 65?
Someone still working — or covered by a working spouse — with employer coverage from active employment at a company with 20 or more employees can usually delay Part B without penalty, then enroll later through a Special Enrollment Period when the job ends. The word qualifying does the heavy lifting: COBRA and retiree coverage do not count, and that distinction catches people every single year. Anyone unsure whether current coverage qualifies should confirm before the window closes, not after.
Frequently Asked Questions
Is Medicare enrollment automatic at 65?
Only for people already receiving Social Security benefits, who are enrolled in Parts A and B automatically. Everyone else must actively sign up through Social Security.
What happens if someone skips Medicare at 65 with no other coverage?
The Part B late penalty adds 10% to the monthly premium for each full 12-month period of delay, and the penalty lasts for life. Part D carries a separate permanent penalty.
Does COBRA count as coverage that allows delaying Medicare?
No. COBRA and retiree coverage do not count as qualifying coverage, and relying on them past 65 can trigger the lifetime Part B penalty.
When does the Initial Enrollment Period start and end?
The window opens 3 months before the month of the 65th birthday and closes 3 months after the birthday month, for 7 months total.
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