6 Months Before Your Birthday
Confirm how you'll get Part A and Part B. If you're already receiving Social Security benefits, Medicare Part A and Part B enrollment happens automatically — your card arrives in the mail a few months before you turn 65. If you're not collecting Social Security yet, nothing happens automatically. You'll need to sign up yourself through the Social Security Administration, online at ssa.gov, by phone, or at a local office.
Decide whether you're keeping employer coverage. If you (or your spouse) are still working and covered by an employer group plan, you may be able to delay Part B without penalty — but only if the coverage counts as current employer coverage. COBRA and retiree coverage do not count for this purpose. This is one of the most consequential decisions on the whole checklist, so if your situation involves current employment, get it confirmed before you decide to delay anything.
Inventory your prescriptions. Write down every medication, dose, and pharmacy you use. You'll need this list to compare drug coverage later, and it takes ten minutes now versus a scramble in your enrollment window.
3 Months Before Your Birthday (Your Enrollment Window Opens)
Enroll in Part A and Part B (if it isn't automatic). Enrolling in the three months before your birthday month means your coverage starts the first day of your birthday month — no gap.
Choose your coverage path. This is the biggest decision at 65, and there are two main routes:
- Original Medicare + a Medicare Supplement (Medigap) + a Part D drug plan. Predictable costs, any doctor that accepts Medicare, no networks.
- A Medicare Advantage plan. Combines your coverage into one plan, often with extra benefits, in exchange for a network and plan rules.
Neither is universally right — the better fit depends on your health, budget, doctors, travel, and prescriptions. A licensed agent can walk through both side by side at no cost to you.
Know your one-time Medigap window. Your 6-month Medigap Open Enrollment Period starts the month you're 65 and enrolled in Part B. During this window, insurers cannot deny you a Medigap policy or charge you more because of your health. This window does not repeat. If Medigap is on your list, this is when the door is wide open.
Pick a drug plan — even if you take nothing. Going 63 or more days without creditable drug coverage after your enrollment period ends triggers a late enrollment penalty that lasts as long as you have Medicare drug coverage. Many people who take no medications choose the lowest-premium Part D plan available simply to avoid a lifetime penalty.
Your Birthday Month
Confirm your coverage is active. Check that your Medicare card arrived, your plan enrollments went through, and your doctors and pharmacy show as in-network (if you chose a plan with a network).
Book your "Welcome to Medicare" visit. Medicare covers a one-time introductory preventive visit within your first 12 months of Part B. It's a review of your health history and a roadmap for the screenings Medicare covers going forward.
After 65 — The Steps People Miss
Stop HSA contributions before Medicare starts. If you have a Health Savings Account, contributions must stop when Medicare begins — and because Part A can be backdated up to 6 months when you enroll late, the safe practice for late enrollees is stopping HSA contributions 6 months before signing up.
Mark the annual calendar. Every year, Medicare's Annual Enrollment Period runs October 15 through December 7. That's your yearly chance to change drug plans or Medicare Advantage plans for the following January.
Review your plan every fall. Plans change their costs, networks, and drug lists every single year. The plan that fit at 65 may not fit at 68. Your Annual Notice of Change letter arrives each September — it's worth reading.