The Basic Rule: Age, Disability, or Kidney Disease
You can get Medicare if you are 65 or older, or if you are under 65 and 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). Most people fall into the first group — those who turn 65. The other two routes exist but cover a smaller population.
Medicare is a federal insurance program run by the Centers for Medicare & Medicaid Services (CMS). It is not means-tested, which means your income and savings do not disqualify you. You do not have to be retired to get it, and you do not have to have worked a certain number of years — though most people do need a work history to be covered.
The key requirement for nearly all people is a work history. You or your spouse must have paid Medicare taxes (the 2.9 percent that comes out of paychecks) for at least 40 quarters — that is 10 years of work, though not necessarily consecutive. If you do not have that history, you can still buy into Medicare at age 65, but the cost is higher.
Key Takeaways
- You become covered at 65 if you have worked and paid Medicare taxes for at least 10 years, or if you have been on SSDI for 24 months, or if you have ESRD or ALS at any age.
- You must sign up during your enrollment window or face a permanent penalty on your premiums, even if you have coverage through an employer.
- If you are still working at 65 and have health insurance through your job, you can delay Medicare Part B without penalty, but you must still sign up for Part A.
- The Social Security Administration handles enrollment for most people, and you can sign up online, by phone, or in person at a local office.
- If you do not have a 10-year work history, you can still buy Medicare at 65, but your Part A premium will be higher than standard.
The Three Routes to Medicare Before Age 65
If you are under 65, you can get Medicare through SSDI, ESRD, or ALS. The SSDI route is the most common. You must have been approved for SSDI and received it for 24 consecutive months. After those 24 months, Medicare begins automatically — you do not have to sign up again.
If you have end-stage renal disease (ESRD), you can get Medicare regardless of age. ESRD means your kidneys function at less than 15 percent of normal capacity, or you are on dialysis, or you have had a kidney transplant. You will need documentation from your nephrologist or dialysis center. Medicare coverage begins the first day of the month you start dialysis or the month you have a transplant.
If you have been diagnosed with ALS (Lou Gehrig's disease), you become covered when ready upon approval for SSDI — you do not have to wait 24 months. This is the only condition with that exception. You will need medical records confirming the diagnosis from your neurologist.
The Work History Requirement and What Happens If You Do Not Have One
Medicare Part A (hospital insurance) requires 40 quarters of work history — roughly 10 years. These quarters do not have to be consecutive, and they do not have to be recent. Work you did 30 years ago counts the same as work you did last year. If you worked part-time, seasonal work, or moved between jobs, the quarters still count as long as you paid Medicare taxes.
If you reach 65 and do not have 40 quarters, you have two options. You can buy Part A at age 65 by paying a monthly premium. The standard premium in 2024 is higher than what most people pay (because most people pay nothing — their work history covers it). You can also continue working and accumulate more quarters; each year of work adds up to four quarters.
If you are married, your spouse's work history can cover you. If your spouse has 40 quarters, you can get Medicare Part A at no cost at 65, even if you have no work history yourself. This is called spousal coverage. You will need your marriage certificate and your spouse's Social Security number to set this up.
When to Sign Up and What Happens If You Miss the important date
Your Initial Enrollment Period (IEP) is the seven-month window that includes the month you turn 65, the three months before, and the three months after. If you sign up during this window, your coverage starts on the first day of the month you turn 65 (or the month after, depending on when you sign up).
If you miss this window, you can still sign up later, but you will face a permanent penalty. For Part B (medical insurance), the penalty is 10 percent of the standard premium for each full year you delayed — and it stays with you for life. For Part D (prescription drug coverage), the penalty is 1 percent of the national base premium per month of delay. These penalties do not go away if you sign up later.
There is one exception: if you have health insurance through your current job (or your spouse's current job), you can delay Part B without penalty. You must sign up for Part A at 65, but you can wait on Part B until you leave that job or lose the coverage. When you do sign up, you have eight months from the date you lose the coverage. This is called the Special Enrollment Period (SEP).
How to Sign Up: The Steps and Where to Go
Most people sign up through the Social Security Administration. You can do this online at ssa.gov, by calling 1-800-772-1213, or by visiting your local Social Security office in person. You will need your birth certificate, proof of citizenship or legal residency, and your bank account information if you want direct deposit.
If you are already receiving Social Security retirement or spousal benefits, you may be signed up for Medicare automatically. The Social Security Administration will send you a notice about three months before you turn 65. If you are not receiving Social Security yet, you must sign up for Medicare separately — do not assume it happens on its own.
If you are under 65 and on SSDI, Medicare is added to your account automatically after 24 months. You will receive a notice in the mail. If you have ESRD or ALS, you will need to contact Social Security or Medicare directly (1-800-MEDICARE) to start the process, because these conditions do not automatically trigger enrollment the way SSDI does.
Documents You Will Need
| What You Are Doing | Documents to Bring |
|---|---|
| Signing up at 65 with a work history | Birth certificate, proof of citizenship or legal residency, Social Security card (or number) |
| Signing up with spousal coverage | Your birth certificate, your spouse's birth certificate, marriage certificate, both Social Security numbers |
| Signing up with ESRD | Medical records from your nephrologist or dialysis center, birth certificate, proof of citizenship |
| Signing up with ALS | Medical records from your neurologist confirming diagnosis, SSDI approval letter, birth certificate |
What Happens After You Sign Up
Once you sign up, the Social Security Administration or Medicare will process your request. This usually takes two to four weeks. You will receive a notice in the mail confirming your coverage start date. About two weeks before that date, you will receive your Medicare card in the mail.
Your Medicare card shows your name, Medicare number, and the date your coverage begins. Keep this card with you when you see a doctor. You will also receive information about your coverage options — Part A (hospital), Part B (medical), Part D (drugs), and Medigap or Medicare Advantage plans. You do not have to choose a plan when ready, but you should review your options before your coverage starts.
If you are signing up late (after your Initial Enrollment Period), your coverage will not start until the first day of the month after you sign up. This is why signing up on time matters — you avoid the gap in coverage and the permanent penalty.
Frequently Asked Questions
Can I sign up for Medicare before I turn 65?
Yes, you can sign up starting three months before you turn 65. The Social Security Administration recommends signing up about three months early so your card arrives before your birthday and coverage starts on time. You cannot sign up more than three months early.
What if I am still working at 65 and do not want Medicare yet?
You must sign up for Part A at 65, even if you are working. You can delay Part B if you have health insurance through your job, but only if you sign up for Part B within eight months of leaving that job. If you do not sign up for Part B when you are supposed to, you will face a permanent penalty.
Do I need to have worked in the United States to get Medicare?
Yes, the 40 quarters of work history must be U.S. work where you paid Medicare taxes. Work done outside the United States does not count. If you are a non-citizen, you must have a valid Social Security number and work history to be covered.
What if my spouse died — can I still use their work history?
Yes. If your spouse had 40 quarters of work history, you can use their record to get Medicare Part A at no cost. You will need your spouse's death certificate and your marriage certificate. This is called widow or widower coverage.
Can I get Medicare if I have never worked?
If you have no work history and no spouse with a work history, you cannot get Medicare at 65 without paying a premium for Part A. You can buy Part A at the standard rate, which is higher than what most people pay. If you are under 65, you can only get Medicare if you have SSDI, ESRD, or ALS.