Turning 65? Your Medicare Enrollment Guide
When to sign up, when your coverage starts, and what happens if you wait, in plain English and with every fact linked to its source.
Chris Frasca Insurance Services · California Insurance License No. 0L86243
Last updated October 5, 2026. Facts come from Medicare.gov and CMS and are linked in the sources below.
The short version: You can sign up during a 7-month Initial Enrollment Period that starts 3 months before the month you turn 65 and ends 3 months after it. Signing up early avoids a delay in coverage. If you wait without a qualifying reason, you may pay a lifelong penalty on Part B.
Your Initial Enrollment Period
Medicare.gov says you are generally first eligible to sign up for Part A (hospital insurance) and Part B (medical insurance) starting 3 months before you turn 65 and ending 3 months after the month you turn 65. That is a 7-month window.
- 3 months before the month you turn 65: your window opens.
- The month you turn 65: your window is open.
- 3 months after that month: your window closes.
Source: Medicare.gov, When can I sign up for Medicare?
When does your coverage start?
Signing up early matters, because signing up late delays your start date.
| If you sign up | Your coverage starts |
|---|---|
| Before the month you turn 65 | The month you turn 65 |
| The month you turn 65, or during the 3 months after | The next month |
If your birthday is on the first of the month, Part A coverage starts the month before you turn 65.
Example: Say your 65th birthday is in December and it isn't on the 1st. Signing up in September, October, or November means your coverage starts December 1. Signing up in December means it starts January 1.
Source: Medicare.gov, When does Medicare coverage start? The example applies those rules.
Do you have to sign up yourself?
If you are already getting Social Security or Railroad Retirement benefits when you turn 65, you are enrolled in Part A and Part B automatically. If you are not, you contact Social Security to sign up. Medicare.gov says applying online with Social Security is the easiest and fastest way.
Most people pay nothing for Part A, because they or a spouse paid Medicare taxes while working, generally for at least 10 years.
Sources: Medicare.gov, How do I sign up for Medicare? and Medicare costs.
Still working at 65?
If you or your spouse are working and have group health coverage through that job, you may be able to wait to sign up for Part B without a penalty. Once you stop working, or lose that coverage if that happens first, you get an 8-month Special Enrollment Period to sign up.
- COBRA doesn't extend your window. Medicare.gov warns not to wait until COBRA ends to sign up for Part B.
- Retiree coverage needs a check. Ask your employer or plan administrator whether signing up for Medicare affects your retiree coverage before you decide.
- Health Savings Accounts: if you have one, stop contributing 6 months before you retire or apply for Social Security benefits, to avoid a tax penalty.
Source: Medicare.gov, Working past 65. According to CMS, coverage through the Individual Health Insurance Marketplace does not give you a Special Enrollment Period.
What if you miss your window?
- Part B late enrollment penalty. In most cases, you pay it for as long as you have Part B. CMS explains that it adds 10% to the standard premium for each full 12-month period you could have had Part B but didn't.
- General Enrollment Period. If you miss your Initial Enrollment Period and don't qualify for a Special Enrollment Period, you may have to wait for the General Enrollment Period, January 1 to March 31. Your coverage then starts the month after you sign up.
Sources: CMS, Enrolling in Medicare Part A & Part B; Medicare.gov, When does Medicare coverage start?
Medigap's one-time window
If you want a Medicare Supplement (Medigap) policy, Medicare.gov says your one-time Medigap enrollment window lasts 6 months and starts the first month you are 65 or older and signed up for Part B. After that period, your options to buy a Medigap policy may be limited and the policy may cost more.
Source: Medicare.gov, When can I buy a Medigap policy?
Your turning-65 checklist
- Mark the first day of your Initial Enrollment Period, 3 months before your birthday month.
- Decide whether you have qualifying employer coverage, and ask about retiree coverage or COBRA before you change anything.
- Sign up for Part A and Part B, or confirm that you were enrolled automatically.
- Write down your doctors, hospital, medications, and pharmacy before you review plan options.
- Review how you want to get your coverage, such as Original Medicare with Medigap and a Part D drug plan, or a Medicare Advantage plan. See the differences.
Common questions
When can I sign up for Medicare when I turn 65?
Your Initial Enrollment Period is a 7-month window. It starts 3 months before the month you turn 65, includes your birthday month, and ends 3 months after it.
When does my coverage start?
If you sign up before the month you turn 65, your coverage starts the month you turn 65. If you sign up in the month you turn 65 or in the 3 months after, it starts the following month. If your birthday is on the 1st, your Part A coverage starts the month before you turn 65.
Do I have to sign up myself?
If you're already getting Social Security or Railroad Retirement benefits when you turn 65, you're enrolled in Part A and Part B automatically. If not, you'll contact Social Security to sign up, and applying online is the easiest and fastest way.
What happens if I wait to sign up for Part B?
In most cases, if you don't sign up for Part B when you're first eligible, you pay a late enrollment penalty for as long as you have Part B. The penalty adds 10% to the standard premium for each full 12 months you could have had Part B but didn't.
I am still working at 65. Do I need Part B right away?
If you or your spouse are still working and have employer group health coverage, you may be able to wait on Part B without a penalty. Once you stop working or lose that coverage, you get an 8-month Special Enrollment Period. COBRA doesn't extend your time to sign up, so check with your employer before you decide.
What does it cost to work with you?
Nothing. The insurance company pays me a commission, not you, so your premium is the same whether you enroll through me or directly with Medicare. There's no fee for a consultation, a plan review, or the yearly check-in.
Turning 65 soon? Let's talk it through
I'll walk you through your dates and your options, with no cost and no pressure. I meet clients in person in Orange County and by phone or video in Orange County and Ventura County. You can also see my turning-65 workshops.
Sources
- Medicare.gov, When can I sign up for Medicare?
- Medicare.gov, When does Medicare coverage start?
- Medicare.gov, How do I sign up for Medicare?
- Medicare.gov, Working past 65
- Medicare.gov, Medicare costs
- Medicare.gov, When can I buy a Medigap policy?
- CMS, Enrolling in Medicare Part A & Part B (publication 11036)
This page is for education and is not connected with or endorsed by the United States government or the federal Medicare program. Your situation may differ, so check with Social Security, Medicare, or a licensed professional about your own dates. I am a licensed insurance agent and do not offer every plan available in your area; see the disclaimer below.