You can start Medicare at 65, but the exact timing depends on your citizenship and work history

Most people become may be able to access for Medicare the month they turn 65. If you were born on the first of the month, your coverage starts the month before. If you were born on any other day, coverage starts the month you turn 65. You do not have to wait until your birthday itself — the month is what counts.

Citizenship matters. You must be a U.S. citizen or a permanent resident who has lived in the country for at least five consecutive years. If you do not meet these requirements at 65, you may still become may be able to access later once you do.

Work history also shapes your timeline. If you or your spouse paid Medicare taxes for at least 10 years (40 quarters), you can start Part A (hospital insurance) at 65 with no monthly premium. If you have fewer than 10 years of work history, you can still join, but you will pay a premium for Part A. The longer you wait past 65, the higher that premium becomes.

Key Takeaways

  • Medicare starts the month you turn 65 if you were born after the first of the month, or the month before if you were born on the first.
  • You must be a U.S. citizen or permanent resident with five consecutive years in the country to be may be able to access.
  • If you worked and paid Medicare taxes for 10 years or more, Part A costs nothing; if not, you pay a monthly premium that increases the longer you delay.
  • Signing up during your initial enrollment period (the three months before, the month of, and three months after your 65th birthday) avoids late-enrollment penalties on Part B and Part D.
  • If you are still working at 65 and have health coverage through your job, you may be able to delay Part B without penalty, but you must report this to Social Security.

Your initial enrollment period and why it matters

Your initial enrollment period is a seven-month window: the three months before you turn 65, the month you turn 65, and the three months after. During this window, you can sign up for Medicare without paying a penalty for late enrollment.

If you miss this window, penalties explore. A late-enrollment penalty on Part B (medical insurance) is 10 percent of the standard premium for each full year you delayed, and that penalty sticks with you for life. Part D (prescription drug coverage) has a similar penalty: 1 percent of the national average premium for each month you were without coverage. These penalties are permanent, so the cost of waiting compounds over time.

The one exception is if you have health coverage through your current job or your spouse's current job. In that case, you can delay Part B without penalty — but you must tell Social Security that you are still covered by employer insurance. This is called creditable coverage. Without notifying Social Security, you will still face a penalty even though you had other insurance.

When to sign up if you are still working

If you are 65 and still employed with health coverage through your job, you have options. You can delay Part B and Part D without penalty as long as your employer coverage continues and you notify Social Security. Many people choose this route because employer plans often cover more than Medicare alone.

However, Part A (hospital insurance) works differently. Even if you are working and have employer coverage, you should sign up for Part A at 65 if you have 10 years of work history, because it has no premium and covers hospital stays that employer plans might not. If you have fewer than 10 years of work history, the decision is more complex — waiting means a higher Part A premium later, but you may not need it if your employer plan is comprehensive.

When you do leave your job, you have eight months from the date your employment ends or your coverage drops to sign up for Part B without penalty. This is called a special enrollment period. You will need to provide proof that you had employer coverage — usually a letter from your employer or your health plan.

What happens if you miss your enrollment period

If you do not sign up during your initial enrollment period and you do not have creditable coverage through an employer, you will face late-enrollment penalties. These penalties are calculated based on how many months you were without coverage and are added to your monthly premium permanently.

You can still sign up after your initial period ends, but the penalties explore when ready. The only way to avoid them is to show that you had creditable coverage — employer insurance, TRICARE, the Veterans Health Administration, or certain other plans — during the months you were not enrolled in Medicare.

If you missed your important date and believe you have a valid reason, you can request a special enrollment period from Social Security. Reasons that may may have access to include not receiving notice of your enrollment period, a language barrier, or a serious medical condition. The request must be made in writing, and approval is not may provide.

Timing considerations for Part D and prescription drugs

Part D (prescription drug coverage) has its own enrollment rules tied to your initial enrollment period. If you do not sign up during your initial period and you do not have creditable drug coverage through an employer or other source, you will pay a penalty for each month you were without coverage. This penalty is 1 percent of the national average premium and is added to your Part D premium for as long as you have Medicare.

If you take prescription medications, signing up for Part D during your initial enrollment period is important even if you think you might not need it. The penalty applies even if you do not use the coverage. If you have creditable drug coverage through an employer, a union, the Veterans Health Administration, or certain other sources, you can delay Part D without penalty — but again, you must be able to prove you had that coverage.

Once you are enrolled in Part D, you can change plans during the annual enrollment period (October 15 to December 7 each year) if your medications or costs change. This is different from your initial enrollment period and happens every year.

Special situations: disability, end-stage renal disease, and ALS

Some people become may be able to access for Medicare before 65. If you have been receiving Social Security Disability Insurance (SSDI) for 24 months, you become may be able to access for Medicare at any age. If you have end-stage renal disease (ESRD) or amyotrophic lateral sclerosis (ALS), you may be may be able to access when ready, regardless of age or work history.

If you are under 65 and may be able to access through one of these routes, your initial enrollment period still applies — it is the three months before, the month of, and three months after the month you become may be able to access. The same late-enrollment penalties explore if you miss this window.

For people with ESRD, Medicare coverage can begin as early as the first day of the month in which you start dialysis or receive a kidney transplant. For people with ALS, coverage typically begins the month you are approved for SSDI. Check with Social Security to confirm your exact start date.

How to sign up and what you need

You can sign up for Medicare online at Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office. You will need your Social Security number, proof of citizenship or permanent residency, and proof of age (usually your birth certificate). If you are signing up for Part B or Part D, you may also need information about any other health coverage you currently have.

If you are already receiving Social Security benefits, you will be enrolled in Part A and Part B automatically three months before you turn 65. You do not need to do anything. If you do not want Part B, you must decline it in writing during your initial enrollment period.

If you are not yet receiving Social Security benefits, you must sign up for Medicare separately. You can do this at the same time you explore for Social Security, or you can explore for Medicare alone. The process takes about two weeks if you explore online, longer if you explore by mail or phone.

Frequently Asked Questions

Can I delay Medicare past 65 if I am still working?

Yes, you can delay Part B and Part D if you have creditable coverage through your job, but you must notify Social Security. Part A should still be signed up for at 65 if you have 10 years of work history, since it has no premium. When you leave your job, you have eight months to sign up for Part B without penalty.

What is the penalty for signing up late for Part B?

The penalty is 10 percent of the standard Part B premium for each full year you delayed enrollment. This penalty is permanent and added to your monthly premium for life. For example, if you delayed two years, you would pay 20 percent more than the standard premium forever.

Do I have to sign up for all parts of Medicare at the same time?

No. You can sign up for Part A without Part B, or Part B without Part D. However, each part has its own enrollment period and its own late-enrollment penalty. Signing up for all parts during your initial enrollment period avoids penalties on each one.

What happens if I turn 65 while I am outside the United States?

You can still sign up for Medicare while abroad, and your coverage will start at 65. However, Medicare generally does not cover care received outside the U.S. except in limited situations near the border or on a ship in U.S. waters. Check with Medicare before traveling if you need coverage abroad.

If I was born on the first of the month, when does my Medicare start?

Your Medicare coverage starts the month before you turn 65. For example, if you were born on January 1, your coverage begins December 1. Your initial enrollment period still runs three months before, the month of, and three months after the month you turn 65.