When You Can Start Medicare: Age, Work Status, and Special Circumstances

You can start Medicare at 65, or earlier if you have a disability, end-stage renal disease, or ALS

The standard age to begin Medicare is 65. You do not have to be retired — you can still be working — but you must be a U.S. citizen or permanent resident who has lived in the country for at least five years. If you are younger than 65, you may still be able to start Medicare if you have been receiving Social Security disability benefits for 24 months, have end-stage renal disease (ESRD), or have been diagnosed with ALS (amyotrophic lateral sclerosis). Each path has different timing rules.

The month you turn 65 is your initial enrollment period. This is a seven-month window: three months before the month you turn 65, the month itself, and three months after. During this window, you can enroll in Medicare Part A (hospital insurance) and Part B (medical insurance) without penalty. If you miss this window and do not have other coverage, you may pay a permanent late-enrollment penalty on your premiums for as long as you have Medicare.

Key Takeaways

You become may be able to access for Medicare the month you turn 65, and your enrollment window opens three months before that date.
If you are already receiving Social Security at 65, you are enrolled in Medicare automatically; if not, you must enroll yourself during your initial enrollment period.
You can start Medicare before 65 if you have been on Social Security disability for 24 months, have end-stage renal disease, or have ALS.
Missing your initial enrollment period can result in a permanent increase to your Part B and Part D premiums, even if you enroll later.
Your coverage start date depends on when you enroll and which month you turn 65 or become may be able to access.

Automatic enrollment if you are already receiving Social Security

If you are already collecting Social Security retirement or disability benefits when you turn 65, Medicare will enroll you automatically. You do not need to do anything. About three months before your 65th birthday, you will receive your Medicare card in the mail. Your Part A coverage begins on the first day of the month you turn 65. Your Part B coverage also begins on the first day of that month, unless you were born on the first day of a month — in that case, it begins the first day of the previous month.

Even though you are enrolled automatically, you should still review your Medicare card when it arrives to make sure the information is correct. Check your name, date of birth, and Medicare number. If anything is wrong, contact Social Security right away to have it corrected before your coverage begins.

Enrolling yourself if you are not yet receiving Social Security

If you are not receiving Social Security benefits when you turn 65, you must enroll in Medicare yourself. You can enroll online through Medicare.gov, by phone at 1-800-MEDICARE (1-800-633-4227), or in person at your local Social Security office. Your initial enrollment period is the same: three months before you turn 65, the month you turn 65, and three months after.

When you enroll, you will choose whether to take Part B. Part A (hospital insurance) is usually free if you or your spouse paid Medicare taxes while working. Part B (medical insurance) has a monthly premium that varies by income. If you are still working and have health insurance through your job, you may be able to delay Part B without penalty — but you must tell Medicare that you are doing so, or you will be charged a late-enrollment penalty later.

Your coverage start date depends on when you enroll. If you enroll during the three months before you turn 65, your coverage begins the first day of the month you turn 65. If you enroll in the month you turn 65 or later, your coverage begins the first day of the month after you enroll.

Starting Medicare before 65 due to disability

If you have been receiving Social Security Disability Insurance (SSDI) for 24 months, you become may be able to access for Medicare at that point, regardless of your age. You do not have to wait until 65. Medicare will enroll you automatically once you have been on SSDI for 24 months. Your Part A coverage begins on the first day of the month you become may be able to access. Part B is also enrolled automatically, and it begins the first day of that same month.

If you are receiving Supplemental Security Income (SSI) instead of SSDI, the rules are different. You must be 65, blind, or disabled to receive SSI, but SSI recipients do not automatically get Medicare. You will need to enroll in Part A and Part B yourself, either online or by phone. Contact Medicare at 1-800-MEDICARE to start the process.

Starting Medicare with end-stage renal disease or ALS

If you have end-stage renal disease (ESRD) — permanent kidney failure requiring dialysis or a transplant — you become may be able to access for Medicare when ready, regardless of age. You do not have to wait 24 months. Your coverage begins the first day of the month you start dialysis, receive a kidney transplant, or are medically determined to have ESRD. You must enroll yourself; Medicare does not enroll you automatically. Contact Medicare at 1-800-MEDICARE or enroll online at Medicare.gov.

If you have been diagnosed with ALS (amyotrophic lateral sclerosis), you become may be able to access for Medicare when ready as well. Unlike SSDI, there is no waiting period. Your coverage begins the first day of the month after you are approved for Social Security disability benefits based on your ALS diagnosis. You will be enrolled automatically once your disability benefits begin.

What happens if you miss your enrollment window

If you do not enroll in Part B during your initial enrollment period and you do not have other may have access to coverage, you will owe a permanent late-enrollment penalty. This penalty is 10 percent of the standard Part B premium for each full 12-month period that you were may be able to access but not enrolled. Once you do enroll, this penalty is added to your monthly premium for as long as you have Medicare — it does not go away.

The same penalty applies to Part D (prescription drug coverage). If you go 63 days or longer without Part D coverage and you do not have other prescription drug coverage that is at least as good, you will owe a penalty when you enroll. The penalty is based on how long you went without coverage.

If you missed your initial enrollment period but have a good reason — such as a serious illness or a mistake by Social Security — you may be able to enroll during a special enrollment period without penalty. Contact Medicare to explain your situation.

Coordinating Medicare with employer health insurance

If you are still working at 65 and your employer offers health insurance, you may be able to delay enrolling in Part B without penalty. This is called creditable coverage. Your employer's plan must be based on current employment, and your employer must have at least 20 employees. If you have creditable coverage, you can delay Part B and enroll later without the late-enrollment penalty.

However, you should still enroll in Part A at 65, even if you are delaying Part B. Part A is usually free, and it protects you in case you need hospital care. When you eventually leave your job or lose your employer coverage, you will have a special enrollment period to sign up for Part B without penalty. You must enroll within eight months of losing your coverage.

Frequently Asked Questions

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

Your initial enrollment period still runs three months before, the month itself, and three months after. Your Part A coverage begins the first day of the month you turn 65, regardless of which day of the month your birthday falls on. Part B also begins the first day of that month.

Can I delay Medicare if I am still working?

You can delay Part B if you have creditable coverage through your employer and your employer has at least 20 employees. You must tell Medicare you are delaying. Part A should still be enrolled at 65. When you leave your job, you have eight months to enroll in Part B without penalty.

Do I have to enroll in Part B if I enroll in Part A?

No. Part A and Part B are separate. You can enroll in Part A without Part B if you wish. However, if you do not enroll in Part B when you are first may be able to access and you do not have other may have access to coverage, you will owe a late-enrollment penalty when you do enroll.

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

You must be a U.S. citizen or permanent resident to get Medicare. If you are a permanent resident, you must have lived in the United States for at least five years. Contact Social Security or Medicare to confirm your may be able to access based on your immigration status.

Can I change my mind after I enroll?

Yes. You have a chance to make changes during the Annual Enrollment Period, which runs from October 15 to December 7 each year. Changes take effect January 1. You may also be able to make changes during a special enrollment period if you have a may have access to life event, such as losing employer coverage.

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.