When You Can Enroll in Medicare: Age, Work History, and Disability Rules

Medicare enrollment opens at 65, but you may may have access to earlier through disability or kidney disease

You can enroll in Medicare at age 65 if you are a U.S. citizen or permanent resident who has lived in the country for at least five years. You do not need to be retired — Medicare is based on age, not income or employment status. However, you can enroll before 65 if you have been receiving Social Security Disability Insurance (SSDI) for at least 24 months, or if you have end-stage renal disease (ESRD) or amyotrophic lateral sclerosis (ALS), regardless of age.

The enrollment window matters. You have a seven-month initial enrollment period centered on your 65th birthday: three months before, the month you turn 65, and three months after. If you miss this window and do not have may have access to coverage elsewhere, you will pay a permanent penalty on your Part B and Part D premiums. The penalty is 10 percent of the standard Part B premium for each full year you delayed, and 1 percent of the standard Part D premium for each month you delayed.

Key Takeaways

You can enroll in Medicare starting three months before you turn 65, during the month of your birthday, or up to three months after.
If you receive Social Security Disability Insurance, you become may be able to access for Medicare after 24 months on SSDI, regardless of your age.
End-stage renal disease and ALS may have access to you for Medicare at any age without the 24-month waiting period.
Missing your initial enrollment window results in a permanent penalty on your premiums unless you had other may have access to health coverage.
You must be a U.S. citizen or permanent resident who has lived in the country for at least five years.

Enrollment at 65: the standard route and the enrollment window

The moment you turn 65, you become may be able to access for Medicare Part A (hospital insurance) and Part B (medical insurance). You do not have to wait until you retire or stop working. Many people continue working past 65 and carry Medicare alongside employer coverage.

Your initial enrollment period runs for seven months total: three months before your 65th birthday, the month of your birthday, and three months after. You can enroll online through Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office. If you enroll during the three months before your birthday, coverage typically starts on the first day of the month you turn 65. If you enroll in the month of your birthday or after, there is usually a one- to three-month delay before coverage begins.

If you miss this window, you can still enroll during the General Enrollment Period, which runs January 1 through March 31 each year, with coverage starting July 1. However, you will owe a permanent penalty on Part B premiums (10 percent per year of delay) and Part D premiums (1 percent per month of delay) for as long as you have Medicare.

Disability: may have access to before 65 through SSDI

If you receive Social Security Disability Insurance, you become may be able to access for Medicare after you have been on SSDI for 24 consecutive months. Your age does not matter — you could be 30 or 50. The 24-month clock starts the month your SSDI benefits begin, not the month you applied.

You do not need to do anything to enroll. Social Security will automatically send you information about Medicare enrollment about three months before your 24-month mark. Your Medicare coverage will start on the first day of the 25th month of your SSDI benefits. Part A (hospital insurance) is automatic; you must choose whether to enroll in Part B (medical insurance) during your initial enrollment period, which is the same seven-month window as for people turning 65.

If you are working and earning above the substantial gainful activity (SGA) limit, you may lose your SSDI benefits, which would also end your Medicare coverage. The SGA limit changes each year; in 2024 it is $1,550 per month for non-blind individuals. Contact Social Security before taking a job to understand how work affects your benefits.

End-stage renal disease and ALS: when ready may be able to access at any age

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 typically begins the first day of the month you start dialysis or the month of your transplant, whichever comes first.

Amyotrophic lateral sclerosis (ALS), also called Lou Gehrig's disease, also qualifies you for Medicare at any age without a waiting period. Your coverage begins the first day of the month you are diagnosed.

If you have ESRD or ALS, Social Security will contact you about enrollment. You will still have an initial enrollment period for Part B and Part D, and the same penalties explore if you miss it. However, because your may be able to access is based on medical condition rather than age or work history, the rules around work and income are different — contact Social Security or Medicare directly to understand how your specific situation affects your coverage.

Work history and citizenship requirements

You do not need a specific amount of work history to enroll in Medicare at 65. However, to receive Part A (hospital insurance) without paying a premium, you or your spouse must have worked and paid Medicare taxes for at least 40 quarters (10 years). If you have fewer than 40 quarters, you can still enroll in Part A, but you will pay a monthly premium.

You must be a U.S. citizen or a permanent resident (green card holder) who has lived in the United States for at least five consecutive years. If you are a permanent resident, you will need to provide proof of your status when you enroll.

If you are not yet a permanent resident but are in the country legally on a visa, you cannot enroll in Medicare until you become a permanent resident and meet the five-year residency requirement. Undocumented immigrants are not may be able to access for Medicare.

Delayed enrollment and late penalties

If you have health coverage through an employer or union while you are still working, you may be able to delay enrolling in Part B without penalty. This is called creditable coverage. You must enroll in Part B within eight months of losing this coverage, or you will owe a permanent penalty.

Part A (hospital insurance) does not carry a late penalty if you have creditable coverage, but Part B and Part D both do. The Part B penalty is 10 percent of the standard premium for each full year you delayed. The Part D penalty is 1 percent of the national average Part D premium for each month you delayed. These penalties stay with you for life.

If you are unsure whether your current coverage counts as creditable, ask your employer or health plan directly. Medicare.gov also has a tool to help you determine this.

Special enrollment periods and life changes

If you miss your initial enrollment period but experience certain life changes, you may be able to enroll during a Special Enrollment Period without penalty. These changes include losing employer coverage, moving out of your plan's service area, or having a family member become may be able to access for Medicare.

You typically have two months from the date of the life change to enroll. For example, if you lose employer coverage on June 15, you can enroll in Medicare from June 15 through August 15 without penalty. You will need to provide documentation of the life change — such as a letter from your employer stating the date coverage ended.

Not all life changes may have access to for a Special Enrollment Period. Contact Medicare at 1-800-MEDICARE to ask whether your situation qualifies.

Frequently Asked Questions

Can I enroll in Medicare before I turn 65 if I am still working?

Yes, if you have been receiving SSDI for 24 months, or if you have ESRD or ALS. Otherwise, you must wait until 65. Working does not delay your may be able to access — you can work and carry Medicare at the same time.

What happens if I miss my initial enrollment period?

You can enroll during the General Enrollment Period (January 1 through March 31), with coverage starting July 1. However, you will owe a permanent penalty on Part B and Part D premiums for as long as you have Medicare, unless you had other may have access to health coverage during the gap.

Do I have to retire to enroll in Medicare at 65?

No. Medicare is based on age, not retirement status. You can work full-time and enroll in Medicare at 65. If you have employer coverage, you may want to coordinate it with Medicare to avoid paying for duplicate coverage.

How do I know if my current health coverage counts as creditable coverage?

Ask your employer or health plan directly whether your coverage is creditable for Medicare purposes. If it is, you can delay enrolling in Part B without penalty as long as you enroll within eight months of losing that coverage.

What if I am a permanent resident but have not lived in the U.S. for five years yet?

You cannot enroll in Medicare until you have been a permanent resident living in the United States for at least five consecutive years. Once you meet this requirement, you can enroll during your initial enrollment period without penalty.

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.