The 7-month window at 65

The enrollment window

Your Initial Enrollment Period (IEP) starts 3 months before the month you turn 65 and lasts 7 months in total. Signing up earlier in the window can help coverage start when you want it to. Waiting until after the window can create gaps or penalties unless an exception applies.

If you have employer coverage

If you or a spouse is still working at a company with 20 or more employees, you may be able to delay Part B without a late penalty. Ask the employer for written confirmation that the group health plan is based on current work. HSA contributions generally must stop once you enroll in Medicare.

Decisions after Parts A and B

Once Original Medicare is in place — or you have chosen Medicare Advantage — you still need a plan for prescriptions and for the remaining medical costs. That is the choice between Medicare Advantage and a Medicare Supplement (also called Medigap), plus Part D.

Common mistakes at 65

Missing the Initial Enrollment Period, assuming a Marketplace plan can continue unchanged, delaying Part B without a valid reason, forgetting Part D, and choosing a plan because a friend likes it are all avoidable. Your doctors, drugs, and travel habits are the better starting point.

Want the full story? Get my book. Medicare 2026: Choose the Right Plan & Avoid Costly Mistakes walks through how Medicare is built. It does not pick a plan.

Still working at 65?

An estimate of delaying Part B with employer coverage, HSAs, and the clock after coverage ends.

COBRA vs Medicare at 65

COBRA is not the same as current employer coverage. Delaying Part B for COBRA can mean a penalty.

The enrollment window

If you have employer coverage

Decisions after Parts A and B

Common mistakes at 65

Medicare eligibility date

Still working at 65?

HSA stop date when Part A starts

COBRA vs Medicare at 65

Where would you like to go next?