How Medicare Part A Works and Who It Covers

Medicare Part A is hospital insurance that covers inpatient hospital stays, skilled nursing facility care, hospice, and some home health services. You become covered on the first day of the month you turn 65, or on the first day of the month you have been receiving Social Security Disability Insurance (SSDI) for 24 months, or when ready if you have end-stage renal disease or ALS. Most people do not pay a monthly premium for Part A because they or their spouse paid Medicare taxes while working.

Part A is not something you request or submit paperwork for in the traditional sense. Instead, you become enrolled automatically if you meet the age and work history requirements. However, you do need to understand what triggers your coverage and when it starts, because missing the window to sign up can cost you.

The key requirement is that you or your spouse paid Medicare taxes for at least 40 quarters (10 years) during your working life. If you did not work that long in the United States, you may still be covered through your spouse's work history, or you may be able to purchase Part A by paying a monthly premium.

Key Takeaways

  • You are automatically enrolled in Medicare Part A the month you turn 65 if you have worked and paid Medicare taxes for at least 10 years.
  • If you are already receiving Social Security benefits before age 65, Medicare Part A starts automatically at 65 with no action required on your part.
  • If you are not yet receiving Social Security at 65, you must contact Social Security to enroll in Medicare, or Part A will not begin.
  • You can purchase Part A coverage if you do not have the required work history, but you will pay a monthly premium that varies based on how many quarters you worked.
  • Part A has no monthly premium for most people, but you will pay a deductible when you use hospital services.

Automatic Enrollment If You Receive Social Security

If you are already receiving Social Security retirement, survivor, or disability benefits before you turn 65, Medicare Part A and Part B are enrolled automatically three months before your 65th birthday. You do not need to do anything. Social Security will send you a Medicare card in the mail about two weeks before your coverage starts on the first day of the month you turn 65.

Check the mail carefully around three months before your birthday. The card will show your Medicare number and the date your coverage begins. If you do not receive it by the time you turn 65, call Social Security at 1-800-772-1213 to confirm your enrollment and request a replacement card.

Enrolling If You Are Not Yet Receiving Social Security

If you are turning 65 but have not yet started Social Security benefits, you must contact Social Security yourself to enroll in Medicare. Automatic enrollment does not happen unless you are already receiving a Social Security payment. This is the most common mistake: people assume Medicare will find them, and then they miss the window.

Contact Social Security at least one month before your 65th birthday. You can call 1-800-772-1213, visit your local Social Security office, or go online to ssa.gov. Tell them you want to enroll in Medicare Part A (and Part B, if you want it). You will need your birth certificate, proof of citizenship or legal residency, and your Social Security number.

If you miss the important date and do not enroll within three months of your 65th birthday, you may face a late enrollment penalty. The penalty is a permanent 10 percent increase to your Part B premium for each year you delayed. Part A does not have a late penalty, but your coverage will not start until you actually enroll.

Work History Requirements and Quarters of Coverage

Medicare Part A requires 40 quarters of coverage, which means you must have paid Medicare taxes for at least 10 years. A quarter is three months. You do not need all 40 quarters to be recent — work from any point in your life counts, as long as you paid into the system.

If you worked for an employer, Medicare taxes were automatically deducted from your paycheck. If you were self-employed, you paid both the employer and employee portions through self-employment tax. Either way, the quarters add up on your Social Security record.

You can check how many quarters you have earned by creating an account on ssa.gov and viewing your Social Security Statement. The statement shows your earnings history year by year. If you have questions about whether specific years count, call Social Security at 1-800-772-1213 and ask them to review your record.

Coverage Through Your Spouse's Work History

If you do not have 40 quarters of your own work history, you may still be covered through your spouse's record. You must be at least 65 years old and married to someone who has 40 quarters of coverage. Your spouse does not need to be enrolled in Medicare themselves — their work history is enough.

To use your spouse's work history, contact Social Security and provide both your Social Security number and your spouse's. Social Security will review both records and determine whether you meet the requirement. If your spouse is deceased, you may still be covered based on their work history if you were married for at least one year.

Purchasing Part A If You Do Not Have Work History

If you do not have 40 quarters of work history and cannot use your spouse's record, you can purchase Part A coverage by paying a monthly premium. The premium amount depends on how many quarters you have worked. As of 2024, the premium ranges from about $278 to $505 per month, but this amount changes each year.

To purchase Part A, contact Social Security at 1-800-772-1213 or visit your local office. You will need to provide proof of citizenship or legal residency and your Social Security number. Once you enroll, your coverage begins on the first day of the month after Social Security processes your request, usually within one to two weeks.

If you are a non-citizen, you must have been a permanent resident for at least five years to be may be able to access to purchase Part A. Undocumented immigrants and those on temporary visas cannot purchase Part A coverage.

What Happens After You Turn 65

Once your Part A coverage begins, you are automatically enrolled in Part B (medical insurance) at the same time, unless you opt out. Part B does have a monthly premium, currently $164.90 per month for most people in 2024, though this changes yearly. If you want Part B, you do not need to do anything — it starts automatically.

If you do not want Part B, you must tell Social Security before your coverage begins. Call 1-800-772-1213 or visit ssa.gov to decline Part B. Be aware that if you decline Part B and later change your mind, you may face a late enrollment penalty on your premium.

You will receive your Medicare card in the mail before your coverage starts. The card shows your Medicare number, which you will use at hospitals, doctors' offices, and pharmacies. Keep it in a safe place and bring it to all medical appointments.

Part A Costs: Deductibles and Copayments

Part A has no monthly premium for most people, but you will pay costs when you use hospital services. For 2024, the Part A deductible for a hospital stay is $1,632 per benefit period. A benefit period starts when you enter the hospital and ends 60 days after you leave. If you are readmitted within 60 days, it is the same benefit period and you do not pay another deductible.

After you pay the deductible, you pay copayments for each day you stay in the hospital. For days 1 through 60, there is no copayment. For days 61 through 90, you pay $408 per day. For days 91 and beyond, you pay $816 per day. These amounts change each year.

Skilled nursing facility care, hospice, and home health services have different cost structures. Part A covers the first 100 days of skilled nursing care in a benefit period, with no copayment for days 1 through 20, and $204 per day for days 21 through 100. Hospice and home health services are covered with no copayment.

Frequently Asked Questions

What if I am still working at 65 — do I still get Medicare Part A?

Yes. Age 65 is the trigger for Medicare enrollment, regardless of whether you are working. If you are still employed and your employer offers health insurance, you can keep that coverage and also have Medicare Part A. Medicare becomes your secondary insurance in this case.

Can I delay Medicare Part A to avoid the deductible?

No. Part A enrollment is based on age or disability status, not on whether you use hospital services. Once you turn 65 and meet the work history requirement, you are enrolled automatically (if you receive Social Security) or you must enroll yourself. You cannot choose to delay it.

Do I need to do anything if I am already receiving disability benefits?

No. If you receive SSDI, Medicare Part A and Part B are enrolled automatically 24 months after your disability benefits begin. You will receive your Medicare card in the mail. If you do not receive it, call Social Security at 1-800-772-1213.

What if I worked outside the United States?

Work performed outside the United States generally does not count toward Medicare coverage, with some exceptions for U.S. citizens working for the U.S. government or certain international organizations. Contact Social Security to discuss your specific work history.

Can I get Part A without Part B?

Yes. Part A and Part B are separate. You can have Part A without Part B, though Part B is enrolled automatically unless you decline it. If you decline Part B at 65 and want it later, you may pay a late enrollment penalty.