Medicare doesn't start on its own when you turn 65

No. You must sign up for Medicare yourself, even if you are already receiving Social Security. Turning 65 does not automatically enroll you. If you miss the important date to sign up, you will face permanent penalties on your premiums — penalties that stay with you for life, not just for a year or two.

The government does not contact you to remind you. You will not receive a letter in the mail telling you it is time. You have to know the important date, know where to sign up, and take action yourself. Most people have a seven-month window to do this without penalty, but that window closes whether you are paying attention or not.

Key Takeaways

  • You must sign up for Medicare yourself during your Initial Enrollment Period, which runs three months before you turn 65, the month you turn 65, and three months after.
  • If you delay signing up past this seven-month window, you will pay a permanent surcharge on your Part B and Part D premiums for as long as you have Medicare.
  • You can sign up online at Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office.
  • If you are still working and have health insurance through your employer, you may be able to delay Part B enrollment without penalty, but you must report this to Medicare.
  • The important date to sign up for the following year is December 7, so missing your Initial Enrollment Period means waiting until then to enroll without penalty.

Your seven-month Initial Enrollment Period window

Your Initial Enrollment Period starts three months before the month you turn 65 and ends three months after. That is seven months total. You can sign up anytime during this window without penalty.

For example, if you turn 65 in June, your window opens in March and closes in September. You can enroll in March, April, May, June, July, August, or September. If you wait until October, you have missed the important date.

Most people should sign up during the month they turn 65 or the month before, straightforward to make sure coverage starts on time. If you sign up in the month you turn 65, your Part A and Part B coverage begins on the first day of that month. If you sign up after the month you turn 65, coverage begins the first day of the month after you sign up.

What happens if you miss the important date

Missing your Initial Enrollment Period triggers a permanent penalty called the Late Enrollment Penalty. This penalty applies to Part B (medical insurance) and Part D (prescription drug coverage) if you delay those parts.

For Part B, the penalty is 10 percent of the standard premium for each full year you delayed enrollment. If you were supposed to sign up in 2024 but do not sign up until 2026, you owe two years of penalties — 20 percent extra on your Part B premium, forever. This does not expire after a certain time. You pay it for the rest of your life.

Part D has a similar structure: 1 percent of the national average premium for each month you delayed. If you go without Part D coverage for 24 months, your penalty is 24 percent of that average, and again, it never goes away.

The only way to avoid this penalty after you have missed the important date is to wait until the next General Enrollment Period, which runs January 1 through March 31 each year. You can enroll then without penalty, but your coverage will not start until July 1 of that year. You will have gone without coverage for months.

Exceptions: when you can delay without penalty

If you are still working and covered by a group health plan through your employer or your spouse's employer, you can delay Part B enrollment without penalty. This is called having creditable coverage. You must report this to Medicare when you eventually sign up, and you must do it within eight months of losing that coverage.

You do not have to report it in advance. But if you do not tell Medicare you had creditable coverage when you enroll, they will assume you delayed without a valid reason and will assess the Late Enrollment Penalty. Keep documentation of your employer coverage — your insurance card, a letter from your employer's benefits office, or your pay stub showing the deduction.

Part A (hospital insurance) has no penalty for delaying if you have creditable coverage, and most people do not need to sign up for Part A at all if they are still working and covered by an employer plan. However, you should still sign up for Part A when you turn 65, even if you delay Part B, because Part A has no premium and covers hospital stays.

How to sign up for Medicare

You have three ways to enroll: online, by phone, or in person.

Online: Go to Medicare.gov and click "Sign up for Medicare." You will need your Social Security number and birth date. The process takes about 10 minutes. You can explore for Part A and Part B at the same time.

By phone: Call 1-800-MEDICARE (1-800-633-4227). Representatives are available Monday through Friday, 8 a.m. to 8 p.m. Eastern time. Have your Social Security number and birth date ready. The call usually takes 15 to 20 minutes.

In person: Visit your local Social Security office. You can find the nearest one at ssa.gov/locator. Bring your Social Security card, birth certificate, and proof of citizenship (passport, naturalization papers, or birth certificate). You do not need an appointment, but wait times vary.

What to do if you already missed the important date

If you are past your Initial Enrollment Period and did not sign up, you have two paths forward.

First, check whether you have a valid reason for the delay. If you were working and had employer coverage, or if you were outside the United States for more than six months, you may may have access to for a Special Enrollment Period. This gives you another eight months to enroll without penalty. You will need to prove the reason — a letter from your employer, a copy of your health insurance card, or documentation of your travel. Call 1-800-MEDICARE to ask whether you may have access to.

If you do not have a valid reason, your next opportunity to enroll without penalty is the General Enrollment Period from January 1 through March 31. Coverage will begin July 1 of that year. You will pay the Late Enrollment Penalty on top of your regular premiums, but at least you will be covered.

Frequently Asked Questions

Do I have to sign up for Part A and Part B at the same time?

No. You can sign up for Part A without Part B if you are still working and have employer coverage. Most people sign up for Part A (hospital insurance) because it has no premium, then delay Part B until they retire. Just tell Medicare you are delaying Part B due to employer coverage so you do not get penalized.

What if I turn 65 while I'm still working?

You can delay Part B without penalty as long as you have health insurance through your job or your spouse's job. You must sign up for Part B within eight months of leaving that job. If you wait longer, the Late Enrollment Penalty applies. Part A has no penalty for delaying, so you can sign up for that anytime.

Can I sign up for Medicare before I turn 65?

Yes. Your Initial Enrollment Period starts three months before you turn 65. You can sign up as early as that date. Many people sign up two or three months before their birthday to make sure everything is in place before coverage begins.

What if Social Security already has my information?

Social Security and Medicare are separate systems. Even if you are receiving Social Security benefits, you must sign up for Medicare separately. The two do not automatically link. You will need to enroll through Medicare.gov, by phone, or at a Social Security office.

Will Medicare contact me if I miss the important date?

No. Medicare does not send reminder letters or make phone calls. You are responsible for knowing the important date and signing up. If you miss it, you will not hear from anyone — you will straightforward start paying penalties when you eventually enroll.