When You Turn 65: Understanding Medicare Enrollment Age

You become may be able to access for Medicare at age 65, with a few exceptions for people with disabilities or end-stage renal disease

Most people in the United States can enroll in Medicare the month they turn 65. You do not have to wait until your birthday itself — you can sign up starting three months before you turn 65, during the month you turn 65, and for three months after. This seven-month window is called your Initial Enrollment Period.

If you are already receiving Social Security benefits before age 65, you will be enrolled in Medicare automatically the month you turn 65. If you are not yet taking Social Security, you will need to enroll yourself through Social Security, Medicare.gov, or your local Social Security office.

Some people become may be able to access for Medicare before 65. You can enroll at any age if you have been receiving Social Security Disability Insurance (SSDI) for 24 months, or if you have end-stage renal disease or amyotrophic lateral sclerosis (ALS). These are the only circumstances that lower the age requirement.

Key Takeaways

You can enroll in Medicare starting three months before you turn 65, during the month you turn 65, or up to three months after — a total window of seven months.
If you are already receiving Social Security, Medicare enrollment happens automatically; if not, you must enroll yourself through Social Security or Medicare.gov.
Missing your Initial Enrollment Period can result in a permanent penalty on your premiums unless you have a may have access to reason for late enrollment.
People under 65 with SSDI for 24 months, end-stage renal disease, or ALS can enroll in Medicare regardless of age.
You can delay enrollment past 65 without penalty only if you or your spouse are still working and covered by an employer health plan.

What happens if you miss the enrollment window

If you do not enroll during your Initial Enrollment Period and you do not have a may have access to reason for the delay, you will face a late enrollment penalty. This penalty is added to your Part B and Part D premiums for as long as you have Medicare — it does not go away after a set time.

The penalty amount depends on how many months you were may be able to access but not enrolled. For Part B, the penalty is 10 percent of the standard premium for each full 12-month period you were late. For Part D (prescription drug coverage), the penalty is 1 percent of the national base beneficiary premium for each month you were late. These amounts change each year.

You can avoid the penalty if you have a may have access to reason for enrolling late. The main may have access to reason is that you or your spouse were covered by an active employer health plan when you turned 65. In that case, you have eight months after your employment or coverage ends to enroll without penalty. Other may have access to reasons include being a federal employee, living outside the United States, or being a member of certain religious groups that do not accept insurance.

Enrolling before you turn 65

You can start the enrollment process three months before your 65th birthday. This is often the easiest time to enroll because you have time to gather documents and ask questions without rushing.

To enroll, you can go to Medicare.gov, call Social Security at 1-800-772-1213, or visit your local Social Security office in person. You will need your Social Security number and proof of citizenship or legal residency. If you are already receiving Social Security, the enrollment may happen without you needing to do anything, but it is worth confirming.

If you are still working and your employer offers health insurance, tell your employer's benefits office that you are turning 65. Some employers require you to enroll in Medicare even while you are still working; others let you stay on the employer plan. The rules depend on your employer's size and your specific situation.

Special situations: Working past 65 and employer coverage

If you are still working at age 65 and your employer has 20 or more employees, you can usually delay enrolling in Medicare Part B without penalty. Your employer's health plan is considered the primary payer, and Medicare becomes secondary. You have until eight months after you leave your job or your coverage ends to enroll in Part B without a late penalty.

This rule applies only to Part B (medical insurance). You should still enroll in Part A (hospital insurance) at 65, even if you are working, because Part A has no premium for most people and covers hospital stays. Part D (prescription drug) has its own rules — if you delay enrollment and later find you need it, you may face a penalty unless you had creditable coverage through your employer.

If your employer has fewer than 20 employees, Medicare becomes your primary payer at 65, and you must enroll. Your employer plan becomes secondary. In this case, you should enroll in Medicare at 65 to avoid penalties.

Medicare enrollment for people under 65

You can enroll in Medicare before age 65 if you have received SSDI for at least 24 consecutive months. The 24-month clock starts from the month Social Security approves your disability claim, not from the month you applied. Once you have been on SSDI for 24 months, you become may be able to access for Medicare automatically — you do not need to explore separately.

If you have end-stage renal disease (ESRD) — permanent kidney failure requiring dialysis or a transplant — you can enroll in Medicare regardless of age. You can enroll in the month you are told you have ESRD, or in the month dialysis treatment begins, whichever comes first. You have a special enrollment period of 12 months to sign up.

People with ALS (Lou Gehrig's disease) can enroll in Medicare when ready upon diagnosis, without waiting. There is no age requirement and no waiting period.

Automatic enrollment and what to expect

If you are receiving Social Security retirement or disability benefits when you turn 65, Social Security will enroll you in Medicare Part A and Part B automatically about three months before your 65th birthday. You will receive a Medicare card in the mail. You do not need to do anything unless you want to decline Part B, which you can do by returning a form that comes with your card.

If you are not yet receiving Social Security, you must enroll yourself. You can do this online at Medicare.gov, by phone at 1-800-MEDICARE (1-800-633-4227), or in person at a Social Security office. The process usually takes 15 to 30 minutes.

After you enroll, your Medicare coverage begins on the first day of the month you turn 65, or the first day of the month after you enroll, whichever is later. If you enroll in January and your birthday is in February, coverage starts February 1. If you enroll in April and your birthday was in February, coverage starts May 1.

Declining Medicare and your options

You can decline Part B when you turn 65 if you are covered by an employer health plan. You must sign a form stating that you are declining coverage. Keep a copy of this form — you will need it to show you had a may have access to reason if you enroll late.

You cannot decline Part A (hospital insurance) if you are receiving Social Security benefits, because enrollment is automatic. If you want to decline Part A, you must contact Social Security and request to be removed from the benefit roll, which means you also stop receiving retirement or disability payments. Most people do not choose this route.

If you decline Part B and later want to enroll, you can do so during the General Enrollment Period, which runs January 1 through March 31 each year. Coverage would begin July 1. However, if you do not have a may have access to reason for the delay, you will owe a late penalty.

Frequently Asked Questions

Can I enroll in Medicare before I turn 65?

Yes, you can start the enrollment process three months before your 65th birthday. If you have SSDI for 24 months, end-stage renal disease, or ALS, you can enroll at any age. Otherwise, you must wait until the three-month window before you turn 65.

What if I am still working at 65 — do I have to enroll in Medicare?

If your employer has 20 or more employees, you can delay Part B enrollment without penalty while you are still covered by the employer plan. You should still enroll in Part A at 65. If your employer has fewer than 20 employees, you must enroll in Medicare at 65 because it becomes your primary payer.

How much does the late enrollment penalty cost?

The penalty varies by year and by how many months you were late. For Part B, it is 10 percent of the standard premium for each 12-month period you delayed. For Part D, it is 1 percent of the national base premium for each month you delayed. The penalty stays on your premiums for life unless you have a may have access to reason for the delay.

Will I be automatically enrolled in Medicare when I turn 65?

Only if you are already receiving Social Security retirement or disability benefits. If you are not yet taking Social Security, you must enroll yourself through Medicare.gov, by phone, or at a Social Security office. Automatic enrollment happens about three months before your 65th birthday.

What if I miss the seven-month enrollment window?

You can still enroll during the General Enrollment Period (January 1 through March 31 each year), but you will owe a late penalty unless you have a may have access to reason, such as employer coverage at the time you turned 65. The penalty is permanent and increases the longer you wait.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.