The turning-65 Medicare checklist

The short version

6 months before your 65th birthday

• Decide whether you're delaying Social Security. Taking Social Security automatically enrolls you in premium-free Part A, which ends HSA contribution eligibility.
• If you have an HSA, stop contributions 6 months before you plan to enroll in Medicare (Part A backdates up to 6 months).
• Ask your employer for a creditable-coverage letter for both medical and drug coverage. Get it in writing.

Read the full working-past-65 guide

3 months before your birthday: your IEP opens

• Your 7-month Initial Enrollment Period starts now.
• Enroll in Part A (and Part B, unless you're delaying with creditable employer coverage).
• Decide between Original Medicare with Medigap or a Medicare Advantage plan. This is the decision that's hardest to reverse later, because Medigap underwriting can apply if you switch.
• Make a list of your current prescriptions and your preferred pharmacy.
• Make a list of doctors and specialists you want to keep.

Compare Advantage and Medigap in detail

Your birthday month

• Your Medigap Open Enrollment Period starts the month you turn 65 and are enrolled in Part B. This is your one window for guaranteed-issue Medigap regardless of health.
• If choosing Original Medicare + Medigap, apply for your Medigap policy now.
• If choosing Medicare Advantage, enroll in your selected plan.
• If you're not on a MAPD, choose a standalone Part D plan to avoid the late penalty.

The 3 months after your birthday

• Your Initial Enrollment Period ends 3 months after your birthday month.
• Cancel any individual marketplace plan or COBRA you no longer need.
• Update beneficiaries and verify Medicare appears on file at each provider you see.
• Watch the mail for your "Medicare & You" handbook (mailed each fall).

Annual maintenance after year one

• October 15 to December 7: Annual Enrollment Period. Re-check your Part D formulary every year.
• January 1 to March 31: Medicare Advantage Open Enrollment if you want to switch or return to Original Medicare.
• Review IRMAA letters that arrive in November or December and decide whether to appeal.

Mistakes that follow you for life

• Missing your IEP without creditable employer coverage (Part B penalty)
• Skipping Part D when first eligible without other creditable drug coverage
• Picking Advantage at 65 and trying to switch to Medigap years later after a health event
• Contributing to an HSA after enrolling in any part of Medicare

Frequently asked questions

When should I start planning for Medicare?

Three to six months before you turn 65. Your Initial Enrollment Period opens three months before your birthday month, so starting earlier gives you time to compare plans, get creditable-coverage letters from any employer, and decide between Advantage and Medigap without rushing.

Do I need to do anything if I already get Social Security?

Not for Parts A and B. If you're already receiving Social Security benefits when you turn 65, you're auto-enrolled in both. Your Medicare card arrives in the mail. You still need to choose a Part D plan and decide between Original Medicare with Medigap or a Medicare Advantage plan.

What if my birthday is on the first of the month?

Your Medicare eligibility shifts to the month before. Your Initial Enrollment Period and Part B coverage start dates all move back one month. We see this trip people up because their Social Security paperwork uses a different effective date than they expect.

Should I sign up online or in person?

Online at ssa.gov is faster for most people. If your situation is complex (delayed Social Security, employer coverage transition, HSA timing, disability dates), an appointment with a local Social Security office can prevent paperwork errors that take months to fix.

What documents do I need?

Your Social Security number, proof of birth, proof of citizenship or lawful presence, and if you're delaying due to employer coverage, the CMS-L564 form signed by your employer plus your IRS-1095 or other proof of group health coverage.