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By YourBest Editorial Team · Updated · How we rank

Checklist · Medicare.gov rules

Turning 65: Your Medicare Checklist

What to do in the months around your 65th birthday so coverage starts on time, you avoid lifetime penalties, and you keep your best Medigap rights.

3 monthsbefore your birthday month: when your Initial Enrollment Period opens
10% / yearPart B penalty for signing up late without other coverage
6 monthsMedigap Open Enrollment once you have Part B
  1. 3 months before your 65th birthday month: your Initial Enrollment Period opens. If you already get Social Security benefits, you’re enrolled in Parts A and B automatically and your card arrives by mail. If not, sign up at ssa.gov.
  2. Decide about Part B if you’re still working. If you have coverage from a group health plan through current work (yours or your spouse’s), you may be able to delay Part B without penalty. Ask your employer whether Medicare would pay first; at employers with fewer than 20 employees it usually does, and you’d need Part B.
  3. Stop HSA contributions in time: once Medicare starts, you can’t contribute to an HSA, and Part A can start up to six months retroactively if you sign up after 65.
  4. Choose your path: Original Medicare plus a Medigap policy and Part D, or a Medicare Advantage plan. See how they compare.
  5. Get drug coverage (Part D, or an Advantage plan that includes it) unless you have creditable coverage, to avoid the Part D penalty.
  6. If you want Medigap, buy it in your Medigap Open Enrollment Period (the six months starting when you’re 65 and have Part B). That is when insurers can’t turn you down or charge more for health conditions.
  7. Check IRMAA: if your income two years ago was high, your premiums will be higher. Use the IRMAA calculator.
  8. Before you enroll, check your doctors and drugs in the Medicare Plan Finder, and keep the yearly notices from any employer plan saying whether its drug coverage is creditable.

Questions

Do I need to sign up for Medicare if I’m already getting Social Security?

No. You’re enrolled in Parts A and B automatically at 65. You can decline Part B if you have qualifying job-based coverage.

What happens if I miss my Initial Enrollment Period?

You can sign up in the General Enrollment Period (January 1 to March 31), with coverage starting the month after you sign up, and you may owe a late enrollment penalty unless you had qualifying coverage.

Can I keep contributing to my HSA after 65?

Not once you’re enrolled in any part of Medicare. Many people stop contributions six months before they enroll because Part A coverage can be backdated up to six months.

Sources

Official sources only, checked October 17, 2026.

  1. Medicare.gov, “Get started with Medicare” — medicare.gov.
  2. Social Security Administration, “Sign up for Medicare” — ssa.gov.
  3. Medicare.gov, “Avoid late enrollment penalties” — medicare.gov.

Educational information, not medical, legal or financial advice. We are not connected with or endorsed by the U.S. government or the federal Medicare program. · Advertiser disclosure

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