Who Medicare Covers and When

You become may be able to access for Medicare at age 65, regardless of your work history or income. If you were born on the first of the month, your coverage starts the month before you turn 65. 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 matters, not the specific date.

You can also become may be able to access before 65 if you have received Social Security Disability Insurance (SSDI) for 24 months, or if you have End-Stage Renal Disease (ESRD) — permanent kidney failure requiring dialysis or transplant — or ALS (amyotrophic lateral sclerosis). People with ALS become may be able to access when ready upon approval for SSDI, without waiting 24 months.

If you are not yet 65 and do not fall into one of these categories, you are not yet may be able to access for Medicare, even if you are retired or have low income. Other programs may help you find coverage in the meantime.

Key Takeaways

  • You become may be able to access for Medicare the month you turn 65, or the month before if your birthday is the first of the month.
  • You can become may be able to access before 65 if you have received SSDI for 24 months, or if you have ALS or ESRD.
  • Enrollment happens through Social Security, either online at ssa.gov, by phone at 1-800-772-1213, or in person at your local Social Security office.
  • Your initial enrollment window is seven months long — three months before the month you turn 65, the month itself, and three months after — and missing it can cost you higher premiums for life.
  • If you are still working and have health insurance through your job, you may be able to delay enrollment without penalty under certain conditions.

The Three Months Before and After Your 65th Birthday

Your Initial Enrollment Period is seven months long: the three months before the month you turn 65, the month you turn 65, and the three months after. During this window, you can enroll in Medicare Part A (hospital insurance) and Part B (medical insurance) without waiting or paying a higher premium later.

If you miss this window, you will pay a late enrollment penalty on Part B for as long as you have Medicare. The penalty is 10 percent of the Part B premium for each full 12 months you were may be able to access but not enrolled. If you were may be able to access at 65 and did not enroll until age 68, you would pay the penalty for the rest of your life — not just for three years, but permanently. This is one of the few Medicare decisions that cannot be undone.

The one exception is if you were covered by a group health plan through your own job (not your spouse's) when you turned 65. In that case, you have an eight-month window after your employment or coverage ends to enroll without penalty. You must enroll within this window, and you will need to show proof that you had employer coverage.

How to Enroll When You Turn 65

You enroll through Social Security, not through Medicare directly. You have three ways to do this: online at ssa.gov, by phone at 1-800-772-1213 (TTY 1-800-325-0778), or in person at your local Social Security office. You can find your local office on the Social Security website.

Online enrollment is the fastest route. You will need to create a my Social Security account if you do not already have one, then select "Medicare" from the menu. The process takes about 10 minutes. If you prefer to call, have your Social Security number and date of birth ready. Wait times are usually shorter early in the week and early in the day.

If you enroll during your Initial Enrollment Period, Part A and Part B coverage typically starts the first day of the month you turn 65 (or the first day of the month before, if your birthday is the first of the month). If you enroll after your Initial Enrollment Period ends, coverage may not start until several months later, depending on when you enroll.

If You Are Still Working at 65

If you are still working and your employer has 20 or more employees, you can delay Part B enrollment without penalty. Your employer's health plan is the primary payer, and Medicare is secondary. You must enroll in Part A, but you can wait to enroll in Part B until you leave your job or lose coverage.

When you do leave your job, you have eight months to enroll in Part B without penalty. You will need to bring proof of your employment and coverage — usually a letter from your employer's benefits department stating the dates you were covered and the number of employees. Without this proof, you will pay the late enrollment penalty.

If your employer has fewer than 20 employees, Medicare becomes primary when you turn 65, and you should enroll in both Part A and Part B during your Initial Enrollment Period. Delaying Part B in this situation will result in a penalty.

Special Situations: SSDI, ALS, and ESRD

If you receive SSDI, you automatically become may be able to access for Medicare after 24 months of receiving benefits. You do not have to explore separately. Social Security will send you information about three months before your 24-month mark. You can enroll online, by phone, or in person using the same methods as anyone else.

If you have ALS, you become may be able to access for Medicare when ready upon approval for SSDI — you do not wait 24 months. Social Security will notify you when your Medicare coverage begins.

If you have ESRD requiring dialysis or a transplant, you become may be able to access for Medicare regardless of age. Your may be able to access begins the first day of the month you start dialysis treatment, or the month of your transplant. If you receive a transplant, your Medicare coverage continues for 36 months after the transplant, even if the transplant fails and you return to dialysis. After 36 months, you must have worked recently enough to may have access to on your own, or you will lose coverage.

What Happens If You Miss Your Enrollment Window

If you miss your Initial Enrollment Period and do not fall into an exception (such as still working with employer coverage), you will pay a late enrollment penalty on Part B. The penalty is 10 percent of the Part B premium for each full 12 months you were may be able to access but not enrolled. This penalty is permanent — it does not go away after a few years.

You can still enroll in Part B during the General Enrollment Period, which runs from January 1 to March 31 each year. Coverage would start July 1 of that year. But you will owe the penalty for the rest of your life, so it is worth enrolling as soon as you realize you missed the important date.

If you believe you have a valid reason for missing your enrollment window — such as not receiving notice from Social Security, or a serious illness that prevented you from enrolling — you can request a Special Enrollment Period. Contact Social Security to explain your situation. They will review your case, but approval is not may provide.

Part A, Part B, and What You Need to Know About Each

Part A covers hospital stays, skilled nursing facility care, hospice, and some home health services. Most people do not pay a monthly premium for Part A if they or their spouse paid Medicare taxes for at least 10 years. If you do not meet this requirement, you can still enroll, but you will pay a monthly premium — the amount varies depending on how many years you or your spouse paid Medicare taxes.

Part B covers doctor visits, outpatient care, medical equipment, and preventive services. Everyone pays a monthly premium for Part B. In 2024, the standard premium is $164.90 per month, but the amount changes each year and may be higher if your income is above a certain level. You will see the exact premium amount when you enroll.

Both Part A and Part B have deductibles and copayments. You are responsible for these costs. Many people also enroll in Part D (prescription drug coverage) or a Medigap or Medicare Advantage plan to help cover these costs, but those are separate decisions made after you enroll in Part A and Part B.

Frequently Asked Questions

What if I turn 65 but I am not yet receiving Social Security?

You can still enroll in Medicare even if you have not started taking Social Security benefits. Enroll through Social Security using the same methods — online, by phone, or in person. Medicare and Social Security are separate programs, so you can start one without starting the other.

Do I have to enroll in Medicare if I have coverage through my spouse's job?

No, if your spouse is still working and you are covered by their employer plan, you can delay Part B enrollment without penalty. You must still enroll in Part A. When your spouse retires or you lose coverage, you have eight months to enroll in Part B without penalty, provided you bring proof of your coverage.

Can I change my mind after I enroll?

Yes, but only during certain windows. If you enroll during your Initial Enrollment Period, you have until March 31 of the following year to make changes. After that, you can make changes only during the Annual Enrollment Period, which runs October 15 to December 7 each year, with coverage changes taking effect January 1.

What if I am not a U.S. citizen?

You must be a U.S. citizen or a lawful permanent resident who has lived in the United States for at least five consecutive years to be may be able to access for Medicare. If you meet these requirements, you can enroll at 65 just like anyone else.

Will I owe back premiums if I enroll late?

No, you will not owe premiums for the months you were not enrolled. However, you will pay the late enrollment penalty on Part B for as long as you have Medicare. This penalty is in addition to your regular monthly premium, not instead of it.