You can start getting Medicare at age 65. That’s the standard eligibility age for most Americans. However, certain medical conditions can qualify you for Medicare much earlier, regardless of your age.
The Standard Age: 65
Medicare is health insurance for people 65 or older. If you’re already receiving Social Security benefits when you turn 65, you’ll be automatically enrolled in Medicare Part A (hospital coverage). If you’re not yet collecting Social Security, you’ll need to sign up yourself during your Initial Enrollment Period, a seven-month window that starts three months before your 65th birthday and ends three months after the month you turn 65.
There’s no option to buy into Medicare early at 62, 63, or 64 just because you want it. Unlike Social Security, which lets you claim reduced benefits starting at 62, Medicare has a hard eligibility line at 65 for most people.
Qualifying Before 65 Through Disability
If you’re under 65 and receiving Social Security disability benefits, you’ll get Medicare automatically after 24 months of disability payments. The clock starts from the date your disability benefits begin, not from when you applied or were diagnosed. So if your disability benefits started in January 2024, your Medicare coverage would kick in January 2026.
There is one major exception to the 24-month wait. If you have ALS (Lou Gehrig’s disease), you get Medicare automatically as soon as your disability benefits start. There is no waiting period at all.
Qualifying Before 65 With Kidney Failure
End-stage renal disease (ESRD) also qualifies you for Medicare at any age, but the rules are more specific. You’re eligible if your kidneys no longer work and you need regular dialysis or have had a kidney transplant. You also need to have worked enough under Social Security, already be receiving Social Security or Railroad Retirement benefits, or be the spouse or dependent child of someone who meets those requirements.
The timing of your coverage depends on your treatment. If you’re on dialysis, Medicare coverage usually starts on the first day of the fourth month of treatments. You can get coverage sooner, starting in the first month, if you enroll in a home dialysis training program at a Medicare-certified facility. If you’re getting a kidney transplant, coverage can begin the month you’re admitted to a Medicare-certified hospital for the transplant, as long as the surgery happens within the next two months.
One detail that catches people off guard: even after you become eligible for Medicare through ESRD, any employer or union health plan you have continues to pay your bills first during a 30-month “coordination period.” Medicare acts as secondary coverage during that time.
What Happens If You’re Still Working at 65
If you’re working at 65 and have health insurance through your employer, whether you need to enroll in Medicare right away depends on the size of the company. If your employer has 20 or more employees, your employer plan stays primary and Medicare becomes secondary. In that case, you can safely delay Medicare Part B enrollment without penalty, because your employer coverage counts as “creditable coverage.”
If your employer has fewer than 20 employees, the situation flips. Medicare becomes your primary insurer at 65, and your employer plan pays second. In this scenario, delaying Part B enrollment could leave you with coverage gaps and trigger a late enrollment penalty.
The Cost of Signing Up Late
Missing your enrollment window for Part B carries a permanent financial penalty. You’ll pay an extra 10% on your monthly Part B premium for every full year you were eligible but didn’t sign up. That penalty never goes away.
For example, if you waited two full years past your eligibility date without creditable coverage, you’d pay a 20% surcharge on top of the standard Part B premium (which is $202.90 per month in 2026) for as long as you have Medicare. Over a decade or two of retirement, that adds up significantly. The Initial Enrollment Period exists specifically to help you avoid this. If you’re approaching 65 and unsure whether your current coverage qualifies as creditable, sorting that out before your enrollment window closes is one of the most financially important things you can do.