Turning 65 opens a 7-month Initial Enrollment Period (IEP). Enroll on time and you lock in coverage smoothly and avoid penalties. Here’s how to make the most of the window.
The pieces you’ll see below: Part A covers hospital stays, Part B covers doctors and outpatient care, Part D covers prescriptions, and Medigap is optional supplemental coverage that helps with what Original Medicare (Parts A and B) leaves you to pay out of pocket.
The 7-Month Window
Your IEP runs 3 months before your birthday month, your birthday month, and 3 months after. If your birthday is June 7, that’s March 1–September 30.
Enroll in the first 3 months and coverage starts the month you turn 65. Enroll during your birthday month or later and coverage starts the first of the following month. Enrolling early is the simplest path.
The Checklist
3 months before your birthday month
- Decide on Part A (usually free — take it) and Part B (has a premium — choose based on your other coverage).
- If you’re already receiving Social Security/RRB benefits, you’re auto-enrolled; just watch for your card.
- If not, apply at ssa.gov/medicare or your local SSA office.
Your birthday month
- Confirm your Part A/B effective date.
- For a Medigap (supplement) plan, note that your 6-month Medigap open enrollment window opens the day Part B begins — the one time insurers can’t deny you or charge more for pre-existing conditions.
3 months after
- Choose a Part D drug plan if you’re not staying on employer coverage.
- Complete enrollment before the window closes to stay penalty-free.
Points to Get Right
Confirm your employer plan counts as creditable coverage. Active coverage from an employer with 20+ employees lets you delay Part B penalty-free. With a smaller employer, Medicare becomes your primary payer at 65, so enroll in Part B on time to stay fully covered.
Working past 65? Know your 8-month clock. If you delayed Part B because of active employer coverage, your Special Enrollment Period is 8 months from the day that job-based coverage ends — not from when you turn 65, and not from when COBRA ends. COBRA and retiree plans don’t extend this window, so enroll in Part B when the employer coverage stops to stay penalty-free.
Move off a marketplace/ACA plan at 65. These generally don’t count as creditable coverage, so switch to Medicare to keep your coverage penalty-free.
Time your last HSA contribution. Part A applies retroactively up to 6 months (never before your 65th birthday). Stop HSA contributions at least 6 months before applying to keep everything clean at tax time.
Set up Part D even without current prescriptions. Keeping creditable drug coverage — gaps under 63 days — protects you from a permanent penalty later.
Use your Medigap window. Enrolling within 6 months guarantees acceptance at the best rates.
Mark your calendar 3 months before your 65th birthday, confirm your current coverage is creditable, and handle your HSA and Medigap timing. Do that and you’ll move into Medicare smoothly.
