You can enroll in Medicare starting three months before you turn 65

Medicare enrollment opens on the first day of the month you turn 65, or three months before — whichever comes first. Most people become may be able to access at 65, but some may have access to earlier if they receive Social Security Disability Insurance (SSDI) for at least 24 months, or if they have end-stage renal disease or ALS. The enrollment window itself lasts seven months: three months before the month you turn 65, the month you turn 65, and three months after. Missing this window can mean paying a permanent penalty on your premiums, so knowing your exact enrollment dates matters.

You do not have to wait until you turn 65 to start thinking about Medicare. Many people begin gathering documents and comparing plans six months ahead. If you are still working and have employer coverage, the rules are different — you may be able to delay enrollment without penalty, but you need to understand the specifics of your situation before the window closes.

Key Takeaways

  • Your initial enrollment window opens three months before you turn 65 and closes three months after, for a total of seven months.
  • If you miss your initial window, you will pay a permanent increase on your Part B and Part D premiums for as long as you have Medicare.
  • You can enroll online at Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office.
  • If you are still working with employer health insurance, you may may have access to for a Special Enrollment Period that lets you delay without penalty.
  • People under 65 who receive SSDI for 24 months, or who have end-stage renal disease or ALS, can enroll in Medicare before 65.

The seven-month enrollment window explained

Your enrollment window is seven months long and centers on your 65th birthday month. It starts on the first day of the third month before you turn 65. For example, if you turn 65 in June, your window opens on March 1. It closes on the last day of the third month after your birthday month — in this example, September 30.

During this window, you can enroll in Medicare Part A (hospital insurance) and Part B (medical insurance) without waiting. If you enroll during the three months before your birthday month, your coverage typically starts on the first day of the month you turn 65. If you enroll in the month you turn 65 or after, your coverage start date shifts — enroll in July, and coverage may not start until September 1.

The exact timing matters because gaps in coverage can be costly. If you are currently uninsured and miss your window, you cannot go back and enroll retroactively. You will have to wait for the next General Enrollment Period, which runs January 1 through March 31 each year, and coverage would not start until July 1 of that year.

What happens if you miss your enrollment window

Missing your initial enrollment window triggers a permanent penalty on your Part B premium. The penalty is 10 percent of the standard Part B premium for each full year you were may be able to access but not enrolled. If you were may be able to access for eight years and did not enroll, you would pay a 80 percent penalty on top of your regular premium for the rest of your life. This penalty does not go away if you enroll later.

Part D (prescription drug coverage) carries a similar penalty: 1 percent of the national average Part D premium for each month you were may be able to access but not enrolled. These penalties stack up quickly and are permanent, so even if you think you do not need Medicare right away, enrolling during your window protects you financially.

The only way to avoid these penalties is to have what Medicare calls creditable coverage — health insurance through an employer, a spouse's employer, COBRA, Medicaid, or the Veterans Administration that is at least as good as Medicare. If you had creditable coverage, you get a Special Enrollment Period after that coverage ends, and you can enroll without penalty.

Enrolling before you turn 65: SSDI, ESRD, and ALS

You do not have to wait until 65 if you receive Social Security Disability Insurance (SSDI). After you have been on SSDI for 24 months, you become may be able to access for Medicare automatically — you do not have to do anything. Your Medicare coverage starts on the 25th month of your SSDI may be able to access. You will receive a Medicare card in the mail before your coverage begins.

Two medical conditions also make you may be able to access before 65: end-stage renal disease (ESRD) and amyotrophic lateral sclerosis (ALS). If you have ESRD, you can enroll in Medicare as soon as you start dialysis or receive a kidney transplant, regardless of age. If you have ALS, you become may be able to access for Medicare when ready upon diagnosis — you do not have to wait for SSDI approval. In both cases, you should contact Social Security or Medicare directly to confirm your enrollment date, as the process is not automatic.

Special enrollment periods if you have employer coverage

If you are still working at 65 and your employer has 20 or more employees, you can delay enrolling in Medicare Part B without penalty. This is called the Special Enrollment Period for employer coverage. You must have health insurance through your employer or your spouse's employer — not a marketplace plan or individual plan. COBRA does not count as employer coverage for this purpose.

When you or your spouse stops working, or when the employer coverage ends, you have eight months to enroll in Medicare Part B without penalty. This eight-month window is separate from your initial seven-month window. You should enroll as soon as the employer coverage ends to avoid any gaps.

Part A (hospital insurance) works differently. If you are still working and have employer coverage, you can delay Part A enrollment without penalty only if your employer has 20 or more employees and you are actively employed. Once you stop working, you should enroll in Part A right away, even if you delay Part B. Part A has no premium for most people, so there is no financial reason to wait.

How to enroll during your window

You have three ways to enroll: online at Medicare.gov, by phone at 1-800-MEDICARE (1-800-633-4227), or in person at your local Social Security office. Online enrollment is the fastest — you can complete it in about 10 minutes if you have your Social Security number and birth date ready. The website walks you through each step and tells you when ready what your coverage will look like.

If you call, a Medicare representative will ask for your Social Security number, date of birth, citizenship status, and whether you want Part A, Part B, or both. The call usually takes 15 to 20 minutes. If you go in person, bring your Social Security card, proof of citizenship (passport, birth certificate, or naturalization papers), and proof of residency (utility bill or lease). Social Security offices are busiest in the mornings and early in the month, so going on a weekday afternoon often means a shorter wait.

You will receive a Medicare card in the mail within two to three weeks of enrolling. Your coverage start date depends on when you enroll within your window, as described above. Do not wait until the last day of your window — mail delays can mean your card arrives after your coverage should have started.

Turning 65 while receiving Social Security

If you are already receiving Social Security retirement or survivor benefits when you turn 65, you are enrolled in Medicare Part A and Part B automatically. You do not have to do anything. Your Medicare card will arrive in the mail about a month before your 65th birthday. Part A starts on the first day of the month you turn 65, and Part B starts the same day.

You still need to enroll in Part D (prescription drug coverage) if you want it. Part D has its own enrollment window: the same seven-month window as Part A and Part B. If you do not enroll in Part D during this window and you do not have other creditable prescription drug coverage, you will pay a penalty when you do enroll later. This penalty is permanent and based on how many months you went without coverage.

Frequently Asked Questions

What if I turn 65 in the middle of the month?

Your enrollment window is based on calendar months, not the exact day you turn 65. If you turn 65 on June 15, your window still opens March 1 and closes September 30. Your coverage will start on June 1 if you enroll before June, or on the first of the following month if you enroll in June or later.

Can I enroll in Medicare if I am still working full-time?

Yes. You can enroll in Medicare at 65 even if you are working. If your employer has 20 or more employees and offers health insurance, you can delay Part B enrollment without penalty. Part A has no premium, so most people enroll in Part A right away and delay Part B until they stop working or lose employer coverage.

Do I lose my employer health insurance when I turn 65?

No. Turning 65 does not automatically end your employer coverage. You keep it as long as you work and your employer offers it. However, once you enroll in Medicare, Medicare becomes your primary insurance and your employer plan becomes secondary. You should tell your employer's benefits office that you have enrolled in Medicare so they can coordinate coverage correctly.

What if I was not a U.S. citizen when I turned 65?

You must be a U.S. citizen or permanent resident to enroll in Medicare. If you became a citizen or permanent resident after 65, you can enroll during a Special Enrollment Period. Contact Social Security or Medicare to confirm your may be able to access and enrollment date.

Can I change my mind after I enroll?

Yes, but only during specific periods. You have until the end of your initial enrollment window to make changes. After that, you can make changes during the Annual Enrollment Period (October 15 through December 7 each year) or if you have a may have access to life event like moving, losing coverage, or getting married.