Medicare Enrollment Checklist for Turning 65 in 2026
October 5, 2026
If you're turning 65 in 2026, your Medicare enrollment checklist starts with one date range: your Initial Enrollment Period, a seven-month window that opens three months before your birthday month, includes your birthday month, and closes three months after it. The Centers for Medicare & Medicaid Services (CMS) is the federal agency that runs Medicare, the federal health insurance program for people age 65 and older and some younger people with disabilities. Missing your window can trigger a late enrollment penalty that follows you for as long as you have Medicare, so the first task on this checklist is simply knowing your dates. From there you'll decide whether to sign up for Part A, Part B, a Part D drug plan, a Medicare Advantage plan, or a Medigap supplement, and in what order.
Quick Answer
To enroll in Medicare when you turn 65, confirm your seven-month Initial Enrollment Period, then apply for Part A and Part B through the Social Security Administration (SSA) at ssa.gov/medicare/sign-up, by phone, or in person. Add a Part D drug plan or choose a Medicare Advantage plan during that same window if you want drug coverage or want to replace Original Medicare. If you're still covered by a current employer's group health plan, you may be able to delay Part B without a penalty until that coverage ends.
Medicare Enrollment Checklist for Turning 65
- Confirm your seven-month Initial Enrollment Period: three months before, your birthday month, and three months after
- Check whether you already receive Social Security or Railroad Retirement Board benefits, since Part A and Part B may start automatically
- Decide if you need to delay Part B because of current employer group coverage
- Create or confirm your account at ssa.gov to apply for Part A and Part B online
- Gather your Social Security number, birth certificate or passport, and work history if applying for the first time
- Compare Original Medicare plus Medigap and Part D against Medicare Advantage before your window closes
- Enroll in a Part D plan or Medicare Advantage plan during your Initial Enrollment Period to avoid a Part D penalty
- Mark your Medigap open enrollment window, which starts once Part B becomes active
Know Your Initial Enrollment Period Window
Your Initial Enrollment Period covers seven months total: the three calendar months before your 65th birthday month, your birthday month itself, and the three calendar months after it. If you sign up during any of the three months before your birthday month, your coverage starts on the first day of your birthday month. If you sign up during your birthday month or any of the three months afterMedicare.gov notes that coverage begins the first day of the month after you sign up. Signing up early in your window, rather than waiting until the last month, means your coverage and any Part D or Medicare Advantage plan start sooner.
If your birthday falls on the first of the month, Medicare treats your window as if your birthday were in the prior month, so confirm your exact dates with the SSA. For a breakdown of every Medicare enrollment window, including the General Enrollment Period and annual plan-switch windows, see medicare enrollment periods explained.
How to Enroll in Medicare, Step by Step
Check whether enrollment is automatic
If you already receive Social Security or Railroad Retirement Board benefits, Part A and Part B typically start automatically on the first of your birthday month, and your Medicare card arrives by mail.
Apply through Social Security if you're not automatically enrolled
Apply online at ssa.gov/medicare/sign-up, by phone, or at a local Social Security office during your Initial Enrollment Period.
Decide on Part B timing if you're still working
If you have qualifying coverage through a current employer, you can often delay Part B without a penalty until that coverage or your job ends.
Add Part D or choose Medicare Advantage
Pick a stand-alone Part D drug plan to pair with Original Medicare, or choose a Medicare Advantage plan that bundles Part A, Part B, and usually drug coverage.
Consider a Medigap policy
If you choose Original Medicare, you get a six-month Medigap open enrollment period starting when your Part B becomes active, your best chance to buy a supplement without medical underwriting.
Confirm your start date and first bill
Check your account for your coverage start date and set up automatic premium payments if you're not having premiums deducted from a Social Security check.
Documents and Information to Have Ready
Before you apply, gather a short list of items so the application goes quickly:
- Your Social Security number
- Birth certificate, passport, or naturalization papers if you're applying for the first time
- Military discharge papers, if applicable
- Information about any current employer coverage, including the employer's name and the plan's start date
- Your existing Medicare card if you already have Part A
- Bank account information if you plan to pay premiums by automatic withdrawal
For a broader look at everything to plan for in the months around your birthday, including dental, vision, and retirement timing, read turning 65 health coverage. If you're unsure whether you even qualify yet, check the rules in medicare eligibility.
Late Enrollment Penalties Are Permanent
If you don't sign up for Part B when you're first eligible and don't qualify for a Special Enrollment Period, your monthly premium can increase 10% for each full 12-month period you could have had Part B but didn't, according to Medicare.gov. That increase applies for as long as you have Part B. Part D works on a similar principle: going 63 days or more without creditable drug coverage can add a permanent penalty to your Part D premium. See medicare late enrollment penalty for how both penalties are calculated.
Already Collecting Social Security, or Still Working at 65?
If you already collect Social Security benefits
You generally don't need to apply separately. The SSA enrolls you in Part A and Part B automatically, with coverage starting the first day of your birthday month, and mails your Medicare card about three months before that date. You can still choose to delay Part B if you have qualifying employer coverage, but you have to tell Social Security to do that.
If you're still working and have employer coverage
If your employer plan counts as qualifying coverage, you can usually delay Part B penalty-free while that coverage continues. Once the job or the coverage ends, you get an 8-month Special Enrollment Period to sign up, detailed in medicare special enrollment period qualifying events. The specific steps for delaying Part B the right way are covered in how to delay medicare part b without penalty, and what to do once that coverage actually ends is covered in enrolling in medicare after losing employer coverage.
Key Numbers for Your Enrollment Window
Plan for Switching Plans Later, Not Just Signing Up Now
The plan you pick during your Initial Enrollment Period isn't necessarily permanent. Each fall, the Medicare Advantage and Part D Annual Enrollment Period lets you change plans for the following year, and Medicare Advantage members get another window each spring to make a one-time switch. The rules for when each window applies are laid out in when can i switch medicare plans. If you chose Original Medicare and a Medigap policy at 65, know that your easiest, lowest-cost chance to buy or change a supplement is during that initial six-month Medigap window, since medical underwriting can apply afterward in most states.
Get free help with your Medicare enrollment checklist
Confirming your dates and comparing Original Medicare against Medicare Advantage can feel like a lot to sort through alone. Get plain-language guidance tailored to your situation, with no pressure to decide on the spot.
Frequently Asked Questions
No separate application is needed in most cases. If you're already receiving Social Security or Railroad Retirement Board benefits before you turn 65, Part A and Part B typically start automatically, and your card arrives in the mail about three months before your birthday month.
You can sign up during the General Enrollment Period, which runs January 1 through March 31 each year, but you may owe a late enrollment penalty unless you qualify for a Special Enrollment Period tied to employer coverage.
Yes. You can choose a Medicare Advantage plan as soon as your Part A and Part B coverage begins, instead of pairing Original Medicare with a separate Part D plan and a Medigap policy.
It's a six-month window that starts the day your Part B coverage becomes active. During that period, insurers in most states can't deny you a Medigap policy or charge more based on your health.
The seven-month structure is the same, but the exact months shift based on your birth month. If your birthday is the first of the month, Medicare calculates your window as if you were born the prior month.