Medicare covers people 65 and older, some younger people with disabilities, and people with end-stage renal disease

You become covered by Medicare automatically when you turn 65, as long as you or your spouse paid Medicare taxes while working. You do not have to do anything on your 65th birthday — coverage starts the month you turn 65. If you were born on the first of the month, coverage starts the month before.

Medicare also covers people under 65 who have been receiving Social Security Disability Insurance (SSDI) for 24 months, people diagnosed with end-stage renal disease (permanent kidney failure requiring dialysis or transplant), and people with ALS (amyotrophic lateral sclerosis, also called Lou Gehrig's disease) from the moment they start receiving SSDI.

If you are not a U.S. citizen, you must have been a permanent resident for at least five years to be covered. If you do not meet these conditions, you may still have other coverage options through your state or employer.

Key Takeaways

  • Medicare covers people 65 and older automatically if they or a spouse paid Medicare taxes for at least 10 years of work.
  • People under 65 on SSDI for 24 months, people with end-stage renal disease, and people with ALS are also covered regardless of age.
  • Medicare has four parts — Part A (hospital), Part B (doctor visits), Part D (prescription drugs), and Part C (an alternative that combines coverage) — and you need to understand which parts you need.
  • You must sign up during your enrollment window or pay a penalty for late enrollment that lasts as long as you have Medicare.
  • Not all doctors, hospitals, or pharmacies accept Medicare, so you should check before scheduling care or filling prescriptions.

What happens when you turn 65

Three months before you turn 65, Social Security will mail you information about Medicare enrollment. Your Initial Enrollment Period runs for seven months: three months before the month you turn 65, the month itself, and three months after. During this window, you can sign up for Medicare without penalty.

If you are already receiving Social Security benefits, Medicare enrollment happens automatically. You will receive your Medicare card in the mail about two weeks before your coverage starts. If you are not yet receiving Social Security, you must sign up for Medicare separately, either online at Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office.

If you miss your Initial Enrollment Period, you can still sign up during the General Enrollment Period, which runs January 1 through March 31 each year. However, you will pay a penalty — a permanent increase to your Part B and Part D premiums — for each 12-month period you were may be able to access but did not sign up. This penalty stays with you for life.

Medicare Part A and Part B: what they cover

Part A covers inpatient hospital stays, skilled nursing facility care (rehabilitation after hospitalization), hospice care, and some home health services. You do not pay a monthly premium for Part A if you or your spouse paid Medicare taxes for at least 10 years. Part A has a deductible — an amount you pay out of pocket before Medicare starts paying — that changes each year. In 2024, the Part A deductible is $1,676 per hospital stay.

Part B covers doctor visits, outpatient care, lab tests, X-rays, ambulance services, and some preventive care like cancer screenings and vaccines. Part B has a monthly premium (in 2024, the standard premium is $174.70 per month, though higher earners pay more) and an annual deductible ($240 in 2024). After you meet your deductible, you typically pay 20 percent of the cost for most services, and Medicare pays 80 percent.

Part A and Part B together are called Original Medicare. They do not cover prescription drugs, dental care, vision care, hearing aids, or long-term care in a nursing home. You can add coverage for these through other programs.

Part C and Part D: your other coverage choices

Part C, also called Medicare Advantage, is an alternative to Original Medicare. Instead of getting Part A and Part B from the federal government, you buy a plan from a private insurance company that is required to cover everything Part A and Part B cover, plus usually prescription drugs and sometimes dental or vision care. Part C plans have networks — lists of doctors and hospitals you should use — and many require referrals to see specialists. If you choose Part C, you still pay Part B premiums to Medicare, plus a premium to the Part C plan.

Part D is prescription drug coverage. If you have Original Medicare (Part A and Part B), you must add Part D or pay a penalty if you go without it for more than 63 days. If you have Part C, prescription drug coverage is usually included. Part D plans vary widely in which drugs they cover and how much you pay, so comparing plans each year matters.

You must choose between Original Medicare and Part C by the end of your Initial Enrollment Period. You can switch between them during the Annual Enrollment Period, which runs October 15 through December 7 each year, with coverage starting January 1.

Who does not may have access to for Medicare

If you are under 65 and do not have SSDI, end-stage renal disease, or ALS, Medicare does not cover you. This includes people who are unemployed, self-employed without sufficient work history, or covered by a spouse's employer plan. You may be covered through your state's Medicaid program, your employer's health plan, or the health insurance marketplace.

If you are a non-citizen, you must have been a permanent resident for at least five years and meet the work history requirement (you or your spouse must have paid Medicare taxes for at least 10 years). Undocumented immigrants are not covered by Medicare, though they may be covered by emergency Medicaid in some states.

If you are a federal employee, railroad employee, or veteran, you may have separate coverage through your employer or the Department of Veterans Affairs instead of or in addition to Medicare. Check with your employer or the VA to understand your options.

What to check before you use your Medicare coverage

Not every doctor, hospital, or pharmacy accepts Medicare. Before you schedule an appointment or fill a prescription, ask the provider whether they accept Medicare and whether they are a participating provider (they accept Medicare's payment as full payment) or a non-participating provider (they may bill you for the difference between their charge and what Medicare pays). Some providers do not accept Medicare at all.

You can search for participating doctors and hospitals on Medicare.gov using the "Care Provider Search" tool. For pharmacies, call ahead or check the pharmacy's website. If your doctor does not accept Medicare, you can still see them, but you will likely pay more out of pocket.

If you have Part C, your plan's network is narrower — you should use doctors and hospitals in the plan's network to avoid higher costs. Check your plan's provider directory before scheduling care.

Frequently Asked Questions

Do I have to sign up for Medicare if I am still working at 65?

If you are still working and covered by your employer's health plan, you can delay signing up for Part B without penalty as long as your employer has 20 or more employees. You must sign up within eight months of leaving your job or losing employer coverage, or you will pay a penalty. Part A has no penalty for delay, but you should still sign up when you turn 65.

What if I worked outside the United States?

Work outside the U.S. does not count toward the 10-year requirement unless you paid U.S. Medicare taxes. If you worked for the U.S. government abroad or for a U.S. employer, those quarters may count. Contact Social Security to review your work history and find out whether you may have access to.

Can my spouse get Medicare if they did not work?

Yes. If you are 65 and covered by Medicare, your spouse can get Medicare at 62 if you have been married for at least one year. Your spouse can also get Medicare at any age if they are caring for your child who is under 16 or disabled. Otherwise, your spouse must wait until 65 or meet the disability or kidney disease requirements.

What happens to my Medicare if I move to another state or country?

Medicare coverage follows you if you move to another U.S. state. If you move outside the U.S., Medicare generally does not cover you except in limited situations (Canada and Mexico for emergency care, and some coverage in U.S. territories). Tell Medicare about your move by calling 1-800-MEDICARE so your address is updated.

Do I lose Medicare if I go back to work?

No. Once you are covered by Medicare, you keep your coverage even if you return to work or earn income. Your coverage does not change based on how much you earn or work.