Medicare Eligibility Requirements: Who Qualifies and When

Medicare is the federal health insurance program for people 65 and older, and for some younger people with disabilities or certain health conditions. Medicare eligibility comes down to three things: your age, your health or disability status, and your residency. Most people become eligible at 65, but the rules have a few twists. You don't have to be retired. You don't have to be collecting Social Security. And your work history affects what you pay, not whether you qualify.

Here's a plain-language guide to who qualifies, what each part requires, and when to sign up.

The Basic Rules

You can get Medicare if you meet one of these:

• You're 65 or older.
• You're under 65 and have received Social Security Disability Insurance (SSDI) or certain Railroad Retirement disability benefits for 24 months.
• You have ALS (Lou Gehrig's disease).
• You have end-stage renal disease (ESRD), meaning permanent kidney failure that needs dialysis or a transplant.

You also need to be a U.S. citizen, or a lawful permanent resident who has lived in the United States continuously for at least five years.

Eligibility at 65

Turning 65 is the most common way into Medicare. A few points clear up the usual confusion:

You don't have to be retired.

You can be working full time and still enroll.

You don't have to be collecting Social Security.

Many people delay Social Security to get a larger monthly check. You can still sign up for Medicare at 65 on your own through the Social Security Administration.

Your spouse's age doesn't matter.

Medicare is individual. A younger spouse has to wait until their own 65th birthday, or qualify another way.

The timing is set.

Your Initial Enrollment Period is seven months long: the three months before your 65th birthday month, your birthday month, and the three months after. Sign up in the three months before your birthday and coverage starts the first day of your birthday month. Sign up later in the window and coverage starts the first day of the month after you apply.

If you're already receiving Social Security or Railroad Retirement benefits at least four months before you turn 65, you're enrolled in Part A and Part B automatically. Your Medicare card arrives in the mail about three months before your birthday.

Eligibility Under 65

Disability.

If you receive SSDI, Medicare starts automatically after you've received disability benefits for 24 months. You don't need to apply separately.

ALS.

If you have ALS and receive SSDI, Medicare starts the same month your disability benefits start. There's no 24-month wait.

ESRD.

If you have permanent kidney failure, you can get Medicare at any age. Coverage usually starts the fourth month of dialysis, or earlier if you do home dialysis training, or the month you're admitted for a kidney transplant. ESRD enrollment isn't automatic, so you'll need to contact Social Security to apply.

Part A: Who Gets It Without a Premium

Part A is hospital insurance. Most people pay no monthly premium (the monthly cost of coverage) for Part A because they, or a spouse, paid Medicare taxes while working for at least 10 years (40 quarters).

That spouse can be a current spouse, a former spouse if the marriage lasted at least 10 years, or a late spouse.

If you don't have 10 years of work history, you can still get Part A. You'd pay a monthly premium for it, with the amount depending on how many quarters you've worked.

Part B: Everyone Pays a Premium

Part B is medical insurance for doctor visits, outpatient care, and medical equipment. Everyone pays a monthly premium for Part B. In 2026, the standard premium is $202.90 per month. People with higher incomes pay more, based on their tax return from two years earlier.

Because Part B has a premium, some people consider skipping it. Be careful. If you don't have other creditable coverage (usually a current employer's plan), delaying Part B leads to a lifelong penalty. More on that below.

Eligibility for Medicare Advantage, Part D, and Medigap

Once you have Original Medicare, you can add to it or replace it. Each option has its own requirements.

Medicare Advantage (Part C).

You need to be enrolled in both Part A and Part B, and live in the plan's service area. Since 2021, people with ESRD can join Medicare Advantage plans too. You can enroll during your Initial Enrollment Period, during the annual Medicare Open Enrollment (October 15 to December 7), or during a Special Enrollment Period if you qualify.

Part D (prescription drug coverage).

You need Part A or Part B, and you have to live in the plan's service area. If you go without drug coverage for 63 days or more after your Initial Enrollment Period ends, you may owe a late enrollment penalty for as long as you have Part D.

Medigap (Medicare Supplement).

You need Part A and Part B. The best time to buy is your Medigap Open Enrollment Period: the six months starting the month you're 65 or older and enrolled in Part B. During that window, insurers can't turn you down or charge more because of your health. After it, they usually can.

Still Working at 65?

If you or your spouse are still working and you're covered by that employer's health plan, you have a choice.

Employer with 20 or more employees.

You can delay Part B without a penalty, because the employer plan pays first. When the job or the coverage ends, you get an eight-month Special Enrollment Period to sign up for Part B.

Employer with fewer than 20 employees.

Medicare usually pays first, so you'll generally want Part A and Part B at 65.

Health savings accounts.

If you contribute to an HSA, enrolling in any part of Medicare stops you from contributing. Some people delay both parts until they stop working. Talk to your benefits office before deciding.

Most people take Part A at 65 either way, since it's usually premium-free.

Late Enrollment Penalties

Medicare adds penalties if you sign up late without other creditable coverage:

Part B.

Your premium goes up 10 percent for every full 12-month period you could have had Part B but didn't. You pay that higher premium for as long as you have Part B.

Part D.

You pay an extra 1 percent of the national base premium for every month you went without creditable drug coverage. That also lasts as long as you have Part D.

Part A (if you have to buy it).

Your premium goes up 10 percent, and you pay the higher amount for twice the number of years you delayed.

These penalties are the main reason to confirm your enrollment timing early, even if you're not planning to use Medicare right away.

How to Check Your Eligibility and Sign Up

• Social Security handles Part A and Part B enrollment. You can apply online at SSA.gov, call 1-800-772-1213, or visit a local office.
• Medicare.gov has an eligibility and premium calculator that gives you a quick answer based on your age and work history.
• A licensed Medicare agent can help you understand what comes after Parts A and B: whether a Medicare Advantage plan, a Medigap plan, or a drug plan makes sense for your doctors and medications. Our Medicare calculator is a simple place to start.

Already Have Part A and Part B? Here's the Next Step

Qualifying for Medicare is step one. Choosing what to add to it is where most of the questions come up. The licensed agents at Clutch City Insurance can walk through Medicare Advantage, Medigap, and Part D options with you, matched to your own doctors and prescriptions. There's no cost and no pressure.

Call 713-870-5044, Monday through Friday, 8:30am to 5pm, or contact us online. Our agents speak 17 languages, and home visits are available across the Houston area.