Independent guide. The Health Advocate is not affiliated with Medicare, Social Security or any insurer. This is general information, not insurance or tax advice. Updated October 2026.
The mail tells you to choose a plan. Nobody tells you the order.
A step-by-step Medicare checklist, from three months before your birthday to your first bill.
✔ Your Initial Enrollment Period is 7 months, centered on your 65th birthday month.
✔ You can delay Part B without penalty only if you have coverage from your own or your spouse’s current job.
✔ Pick a path: Original Medicare (often with Medigap and Part D) or Medicare Advantage.
✔ Your best chance to buy Medigap without health questions is the 6 months after your Part B starts.
Turning 65 brings a flood of mail about Medicare: postcards, brochures, plan ads and invitations to “free seminars.” Very little of it explains what you actually have to do, or in what order. This checklist does.
Your Medicare timeline at a glance
| When | What to do |
|---|---|
| 4 to 6 months before your 65th birthday month | Decide whether you’ll delay Part B. Ask your employer whether your coverage qualifies. Stop HSA contributions if you’ll enroll. |
| 3 months before | Your Initial Enrollment Period opens. Sign up now if you want coverage to start on the first day of your birthday month. |
| Your birthday month | Still in your window. If you sign up now, coverage starts the first of next month. |
| 3 months after | Your window closes at the end of this month. |
| First 6 months of Part B (at 65+) | Your Medigap open enrollment period. Buy a policy now if you want one. |
| Every October 15 to December 7 | Review your plan for the coming year. |
Step 1: Know your enrollment window
Your Initial Enrollment Period lasts seven months: the three months before the month you turn 65, your birthday month, and the three months after.
When your coverage starts depends on when you sign up. Enroll in any of the three months before your birthday month, and coverage starts on the first day of your birthday month. Enroll in your birthday month or later in the window, and coverage starts the first day of the following month. Signing up early avoids a gap.
If you’re already receiving Social Security retirement benefits at least four months before you turn 65, you’ll usually be enrolled in Parts A and B automatically, and your red, white and blue Medicare card will arrive in the mail about three months before your birthday. If you’re not collecting Social Security yet, you need to sign up yourself, online at ssa.gov, by phone, or at a Social Security office.
Step 2: Decide whether you can delay Part B
Part A (hospital coverage) is premium-free for most people, so most people take it at 65. Part B (doctor visits, outpatient care) has a monthly premium, so people who are still working sometimes delay it.
You can delay Part B without a penalty if you’re covered by a group health plan based on current employment, yours or your spouse’s. If the employer has fewer than 20 employees, Medicare usually pays first, and you’ll generally need Part B anyway. When the job or the coverage ends, whichever comes first, you have an 8-month Special Enrollment Period to sign up for Part B.
Careful with COBRA and retiree coverage. Neither counts as coverage from current employment. If you rely on COBRA instead of signing up for Part B, you can end up with a late penalty and a gap in coverage. Retiree plans usually expect Medicare to pay first.
If you miss your window and don’t qualify for a Special Enrollment Period, the General Enrollment Period runs January 1 to March 31 each year, with coverage starting the month after you sign up. You may owe a lifelong late penalty of 10% for each full year you were without Part B.
Step 3: Choose your path
There are two main ways to get Medicare coverage. Neither is right for everyone.
- See any doctor or hospital nationwide that accepts Medicare
- Usually no referrals needed
- Pays 80% of most Part B services after the deductible; no yearly out-of-pocket cap
- Most people add a Part D drug plan, and many add Medigap to cover the gaps
- Run by private insurers; often includes drug coverage
- Usually uses a provider network; may need referrals or prior authorization
- Has a yearly in-network out-of-pocket cap (up to $9,850 in 2027)
- Often adds extras like dental, vision or hearing allowances
A few questions help sort it out: Do you want to keep specific doctors? Do you travel or spend part of the year in another state? Would you rather pay more each month for predictable costs, or less each month and more when you use care? Do you have a health condition that needs frequent specialist visits?
Step 4: Don’t skip drug coverage
If you choose Original Medicare, you’ll need a separate Part D plan for prescriptions (most Medicare Advantage plans include it). Even if you take no medications now, enroll in Part D or keep other creditable drug coverage. Going 63 days or more without it after your window ends triggers a late penalty that usually lasts for life.
In 2027, covered Part D drug costs are capped at $2,400 a year out of pocket, and plans can charge a deductible of up to $700.
Step 5: Mark your Medigap window
If you choose Original Medicare, a Medigap (Medicare Supplement) policy can cover much of the 20% coinsurance and deductibles Medicare leaves behind. Your Medigap open enrollment period is a one-time, 6-month window that starts the first month you’re 65 or older and enrolled in Part B. During it, insurers can’t deny you or charge more because of your health. After it ends, in most states they can.
If you’re delaying Part B because you’re still working, your Medigap window doesn’t start until Part B does. That’s another reason to plan the timing.
Step 6: Stop HSA contributions in time
You can’t contribute to a Health Savings Account once you’re enrolled in Medicare. If you sign up for Part A after 65, coverage can be backdated up to six months, so plan to stop contributions about six months before you enroll. Money already in the HSA can still pay for qualified medical expenses, including Medicare Part B, Part D and Medicare Advantage premiums.
Step 7: Budget for the costs
| Cost | 2026 (official) | 2027 |
|---|---|---|
| Part A premium | $0 for most people | $0 for most people |
| Part A hospital deductible (per benefit period) | $1,736 | Announced in November (projected about $1,788) |
| Part B standard premium | $202.90/month | Announced in November (projected about $209.50) |
| Part B deductible | $283 | Announced in November (projected about $292) |
| Part D deductible (maximum) | $615 | $700 |
| Part D out-of-pocket cap | $2,100 | $2,400 |
Higher earners pay more for Part B and Part D through an income-related adjustment (IRMAA). It’s based on the tax return from two years earlier, so 2027 premiums use your 2025 income. If your income dropped because you retired, you can ask Social Security to use more recent income with form SSA-44.
Step 8: Get free help, and protect your Medicare number
Every state has a State Health Insurance Assistance Program (SHIP) with free, unbiased one-on-one Medicare counseling. Counselors don’t sell plans. Find yours at shiphelp.org or call 1-800-MEDICARE.
Once your card arrives, treat your Medicare number like a credit card number. Medicare won’t call you to ask for it, and anyone offering free gifts, tests or braces in exchange for it is likely running a scam.
Turning-65 checklist
- Write down your Initial Enrollment Period dates.
- If still working, confirm in writing that your job coverage lets you delay Part B.
- Stop HSA contributions about 6 months before enrolling.
- Sign up for Part A and B (or confirm automatic enrollment).
- Choose Original Medicare or Medicare Advantage.
- Join a Part D plan if your choice doesn’t include drug coverage.
- Buy Medigap within your 6-month window if you want it.
- Set a reminder for October 15 to review your plan each year.
Quick answers
Do I have to sign up for Medicare at 65 if I’m still working?
Not always. If you have coverage from your own or your spouse’s current job at an employer with 20 or more employees, you can usually delay Part B without penalty. Many people still take premium-free Part A, unless they want to keep contributing to an HSA.
Is Medicare’s full retirement age the same as Social Security’s?
No. Medicare eligibility starts at 65. Social Security’s full retirement age is 67 for people born in 1960 or later. You can sign up for Medicare without claiming Social Security.
Can I change my mind after choosing Medicare Advantage?
Yes. You can switch during open enrollment each fall or from January 1 to March 31. But if you switch to Original Medicare later, you may not be able to buy a Medigap policy without health questions.
What if I’m under 65 and on disability?
You’re usually enrolled automatically after 24 months of Social Security disability benefits. When you turn 65, you get a new enrollment period and new Medigap rights.
Sources: Medicare.gov (when coverage starts, Part B enrollment, Medigap open enrollment); Social Security Administration (Medicare enrollment, IRMAA, form SSA-44); CMS, 2026 Medicare Parts A and B premiums and deductibles; CMS, CY 2027 Part D parameters; 2026 Medicare Trustees Report (2027 projections); IRS Publication 969.
Know your window, settle the Part B question, then choose your coverage.
See the 7 costliest Medicare mistakes →