When You Can Join Medicare: Age, Work History, and Special Circumstances

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

Medicare opens to you at age 65 no matter your work history. If you are younger, you may still join if you have been receiving Social Security disability benefits for 24 months, have end-stage renal disease (permanent kidney failure), or have been diagnosed with ALS (amyotrophic lateral sclerosis). The month you turn 65, or the month your 24-month disability period ends, is when your coverage can start — but you have to sign up during the right window or face a penalty that lasts for life.

The timing matters because Medicare has three separate enrollment periods, and missing your window costs you money every month you stay enrolled. This guide explains when you become may be able to access, when you must sign up, and what happens if you miss the important date.

Key Takeaways

You become may be able to access for Medicare the month you turn 65, or when ready if you have been on Social Security disability for 24 months, have end-stage renal disease, or have ALS.
Your Initial Enrollment Period is the three months before you turn 65, the month you turn 65, and the three months after — seven months total to sign up without penalty.
If you miss your Initial Enrollment Period and do not have employer coverage, you pay a permanent 10 percent penalty on Part B premiums for every 12 months you stayed uninsured.
People with employer coverage through a current job can delay enrollment past 65 without penalty, but must sign up within eight months of losing that coverage.
You can sign up online at Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office.

Joining Medicare at 65

The standard entry point is the month you turn 65. You do not need to have worked a certain number of years — Medicare is based on age alone at 65. If you were born on any day in a given month, you become may be able to access the first day of that month. Someone born on March 15 becomes may be able to access March 1; someone born on March 31 also becomes may be able to access March 1.

Your Initial Enrollment Period runs for seven months: the three months before the month you turn 65, the month you turn 65 itself, and the three months after. If you turn 65 in June, your window opens March 1 and closes September 30. Sign up anytime during those seven months and your coverage starts the month you turn 65 (or the first day of the following month, depending on when you sign up).

If you sign up after your Initial Enrollment Period closes, your coverage does not start when ready — it starts the first day of the month after you sign up. More importantly, you face a permanent penalty on your Part B premium (the outpatient coverage) of 10 percent for each 12-month period you went without coverage. Someone who waits two years past 65 to sign up pays 20 percent more every month for life.

Joining Before 65 Because of Disability

You can join Medicare before 65 if you have been receiving Social Security Disability Insurance (SSDI) or Railroad Retirement Board disability benefits for at least 24 months. The 24 months do not have to be consecutive — they count from the date your benefits started, even if you had a gap. Once you reach 24 months of benefits, you become may be able to access the month after that 24-month mark passes.

Your Initial Enrollment Period for disability-based Medicare is the three months before you become may be able to access, the month you become may be able to access, and the three months after — the same seven-month window as age-based enrollment. If you miss this window, the same 10 percent permanent penalty applies to Part B.

If you are already receiving SSDI when you turn 65, your coverage does not change — you straightforward transition from disability-based Medicare to age-based Medicare on your 65th birthday. Social Security handles this automatically; you do not need to re-enroll.

Joining with End-Stage Renal Disease or ALS

You become may be able to access for Medicare when ready upon diagnosis if you have end-stage renal disease (ESRD) — permanent kidney failure requiring dialysis or a transplant — or ALS (Lou Gehrig's disease). You do not have to wait for a disability information or reach any age threshold. Your doctor or dialysis center reports your diagnosis to Social Security, and your may be able to access begins the first day of the month in which you are diagnosed or the month dialysis starts, whichever is later.

Your Initial Enrollment Period is still seven months: three months before may be able to access, the month of may be able to access, and three months after. If you have ESRD and later receive a kidney transplant, your Medicare coverage continues for 36 months after the transplant, even if you no longer need dialysis. After 36 months, you must have another reason to stay on Medicare (age 65, ongoing disability, or another may have access to condition) or your coverage ends.

Delaying Enrollment If You Have Employer Coverage

If you or your spouse are still working and covered by an employer health plan, you can delay Medicare enrollment past 65 without penalty. This is called having creditable coverage. You must sign up within eight months of losing that coverage — whether through retirement, job loss, or the employer plan ending. The eight-month window is your Special Enrollment Period.

If you miss the eight-month window after losing employer coverage, you face the same 10 percent permanent penalty on Part B as anyone else who enrolls late. The penalty applies for each 12-month period you were may be able to access but not enrolled and did not have creditable coverage.

Tell Medicare that you have employer coverage when you sign up, or contact Social Security to report it. Medicare uses this information to avoid sending you bills or penalties during the months you are covered elsewhere.

How to Sign Up During Your Enrollment Period

You have three ways to sign up: online, by phone, or in person. The online method is fastest. Go to Medicare.gov, click "Sign Up for Medicare," and follow the steps. You will need your Social Security number and information about any current health coverage. The process takes about 10 minutes, and you receive a confirmation number when ready.

To sign up 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, and Saturday 9 a.m. to 1 p.m. Eastern time. Have your Social Security number and insurance information ready. The call usually takes 15 to 20 minutes.

You can also visit your local Social Security office in person. Find the nearest office at ssa.gov/locator. Bring your Social Security card, proof of citizenship or legal residency, and information about any current coverage. Offices are open Monday through Friday, 9 a.m. to 4 p.m., though hours vary by location.

What Happens After You Sign Up

After you sign up, Social Security processes your process and mails you a Medicare card within two to three weeks. Your coverage starts on the date you chose during enrollment — usually the first day of the month you turn 65 or become may be able to access. You do not have to do anything else; Medicare coverage is automatic once you are enrolled.

Your Medicare card shows your name, Social Security number, and the date your coverage begins. Keep it with you at medical appointments. If you lose it, you can request a replacement at Medicare.gov or by calling 1-800-MEDICARE.

If you enrolled in Original Medicare (Part A and Part B), you will receive information about prescription drug coverage (Part D) and supplemental insurance (Medigap) options. You do not have to buy these, but if you want them, you have a limited time to sign up without penalty. If you enrolled in a Medicare Advantage plan (Part C), that plan handles your drug coverage and supplemental benefits.

Frequently Asked Questions

What if I turn 65 but am still working and do not want Medicare yet?

If your employer plan is creditable coverage, you can delay Medicare without penalty. You have eight months after you leave the job or lose the coverage to sign up. If you do not have employer coverage and do not sign up during your Initial Enrollment Period, you will owe a permanent 10 percent penalty on Part B premiums.

Can I sign up for Medicare before I turn 65?

You can sign up starting three months before you turn 65. Your Initial Enrollment Period opens three months before the month you turn 65. Signing up early does not start your coverage early — it starts the month you turn 65 — but it ensures you meet the important date.

What if I miss my Initial Enrollment Period?

You can still sign up, but your coverage will not start until the first day of the month after you enroll, and you will owe a permanent penalty on Part B. The penalty is 10 percent of the standard Part B premium for each 12-month period you were may be able to access but not enrolled. This penalty stays with you for life, even if you switch plans later.

Do I have to be a U.S. citizen to join Medicare?

You must be a U.S. citizen or a lawful permanent resident who has lived in the United States for at least five years. Bring proof of citizenship or legal residency when you sign up. A passport, birth certificate, or naturalization papers all work.

If I have SSDI, do I automatically get Medicare after 24 months?

No. Social Security notifies you when you become may be able to access, but you still have to sign up. You have seven months (three before, the month of, and three after your may be able to access month) to enroll without penalty. If you do not sign up during this window, you face the same late-enrollment penalty as anyone else.

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.