Medicare Part A ‘hospital insurance’ – coverage of inpatient care

What is Medicare Part A?

Part A coverage – or “hospital insurance” – pays for a broad range of inpatient care in hospitals, skilled nursing facilities, and critical access hospitals. And, while it does not cover long-term custodial care, Medicare Part A does cover some home health care and hospice services.

What does Medicare Part A cover?

The list of expenses covered by Medicare Part A includes:²

• Hospital inpatient care, including a semi-private room (unless a private room is medically necessary), meals, and prescription drugs that are administered while you’re an inpatient.
• Inpatient care in a skilled nursing facility (For coverage to be provided for the skilled nursing facility stay, Original Medicare requires a three-day inpatient hospital stay prior to the skilled nursing facility stay.³ Note that observation status is not the same thing as inpatient status, and that Medicare does not cover long-term care for people who only need assistance with the activities of daily living.
• Hospice care and home health care services when medically necessary (home health care includes intermittent skilled nursing, physical therapy, speech-language pathology, some medical supplies and equipment, but not assistance with daily living if that’s the only care you need, as that would be categorized under long-term care).
• Inpatient care in a religious non-medical health care institution.⁴
• Blood – If no free blood bank blood is available, Part A pays for the patient’s blood needs after the enrollee pays for the first three units. (All of the standardized Medicare Supplement (“Medigap”) plans, which are an extra insurance product you buy from a private company and that can cover some out of pocket expenses that Original Medicare does not, cover at least some of the cost of the first three pints of blood, and most of them cover the full cost.)⁵
• Inpatient mental health care. (If it’s in a psychiatric facility, coverage is limited to 190 days in the enrollee’s lifetime.)
  

How do I enroll in Medicare Part A?

If you are already receiving Social Security or Railroad Retirement Board (RRB) benefits, the government automatically enrolls you in Medicare Part A at no cost when you reach age 65.⁶ Look for your Medicare card to automatically arrive in the mail three months prior to your 65th birthday (or the 25th month of a disability, as you become eligible for Medicare after two years of being disabled and receiving Social Security Disability benefits).

If you have ALS (amyotrophic lateral sclerosis, also called Lou Gehrig’s disease), you’ll get Part A automatically the month your Social Security disability benefits begin, however. If you’re close to 65 years old, but not getting Social Security or RRB benefits, you’ll need to sign up for Medicare. If you have End-Stage Renal Disease (ESRD) and want Medicare, you’ll need to sign up for it.

Regardless of age, individuals diagnosed with amyotrophic lateral sclerosis (ALS) receive their Medicare Part A card through the mail the month their disability benefits begin (and there is no longer a five-month waiting period for disability benefits to begin after an ALS diagnosis). People with end-stage renal disease (kidney failure) are also eligible for Medicare coverage, starting either the fourth month of dialysis or, if the patient enrolls in a home dialysis program, the first month of dialysis.⁷

When do I enroll in Medicare Part A?

Individuals eligible for Medicare because of their work history and age who are not automatically enrolled in Medicare Part A have a seven-month window of time to enroll, beginning three months prior to the month they turn 65 and continuing for three months after their birthday month. This is called the Initial Enrollment Period.

If you’re not eligible for premium-free Medicare Part A and you delay your enrollment until after Initial Enrollment Period, you’ll be subject to additional premiums for Part A and will likely need to wait until the General Enrollment Period to sign up.⁸  (Most people are eligible for premium-free Part A,¹ but if you or your spouse haven’t paid at least ten years of payroll taxes, you’d have to pay for Medicare Part A. To qualify for premium-free Medicare based on your spouse’s work record, your spouse must be at least 62 years old.)⁷

Learn more about Medicare’s coverage of end-stage renal disease (ESRD) and ALS.

What does Medicare Part A cost?

How much you pay for Medicare Part A coverage depends on your work history. If you or your spouse worked and paid into Medicare through payroll taxes for at least 40 quarters (10 or more years), you pay nothing each month for Medicare Part A. (If you’re qualifying based on your spouse’s work record, your spouse must be at least 62 years old.⁷ If not, you have to pay for Medicare Part A even if your spouse paid payroll taxes for 10+ years).

There are some requirements to be aware of in terms of the length of the marriage if you’re enrolling based on your spouse’s work history.⁹ Also, since the Defense of Marriage Act was ruled unconstitutional in 2013, the Social Security Administration has processed premium-free Medicare A enrollments based on the work history of enrollees’ same-sex partners.¹⁰

If you or your spouse worked and paid into Medicare for between 7.5 and 10 years, you’ll pay $285 a month for Medicare Part A in 2025.¹¹ If the work history was less than 7.5 years, the premium is $518 a month in 2025. These amounts generally increase modestly each year, as was the case for 2025. The 2026 amounts had not yet been finalized by CMS as of mid-October 2025.

Who doesn't have to pay a premium for Medicare Part A?

If you are 65 and you or your spouse has paid Medicare taxes for at least 10 years, you don’t pay a premium for Part A.¹²

You may also not have to pay the premium:

• If you haven’t reached age 65, but you’re disabled and you’ve been receiving Social Security benefits or Railroad Retirement Board disability benefits for two years.
• You have end-stage renal disease (ESRD) and are receiving dialysis, and either you or your spouse or parent (if you’re a dependent child) worked and paid Medicare taxes for at least 10 years. Coverage typically begins the first day of your fourth month of dialysis, but it can begin in your first month of dialysis if you use in-home dialysis treatment.¹³

You have been diagnosed with ALS and are eligible for Social Security Disability Insurance (SSDI). Medicare coverage begins as soon as your SSDI begins, and Medicare Part A has no premiums as long as you or your spouse (or parent, if you’re a dependent child) worked and paid Medicare taxes for at least 10 years.

How much of my inpatient healthcare charges will Medicare Part A cover?

Medicare Part A pays the majority of the Medicare-approved charges for inpatient health care services. However, you must pay a deductible ($1,676 in 2025) ¹⁴ for each benefit period. Note that this isn’t the same as deductibles on most other types of health insurance, as the deductible is for each benefit period rather than each year.

And there are per diem copays that apply to extended hospital stays. If your hospitalization lasts more than 60 days in 2025, you’ll pay $419 per day for days 61 through 90, ¹⁴ in addition to the deductible you already paid for that benefit period (if you are discharged from the hospital before the 61st day, you only pay the deductible).

If you’re hospitalized for longer than 90 days, you have 60 lifetime reserve days that you can use – during those days, you’ll pay $838 per day in 2025. ¹⁴ Once the reserve days are used up, Medicare doesn’t pay any additional charges during that benefit period (a benefit period begins on the day you’re admitted to the hospital, and ends when you’ve been out of the hospital for 60 days).

All of these amounts will be updated for 2026 in the fall of 2025.

It’s rare for beneficiaries to be hospitalized more than 60 days,¹⁵ but not unheard of – which is why a Medigap supplement can be an important addition to Original Medicare in retirement for some people, including those who don’t have supplemental coverage from an employer-sponsored plan or Medicaid to pay the costs Original Medicare doesn’t cover.

Medigap supplemental coverage may be important even for beneficiaries with more modest medical needs, as most of the available plans will cover some or all of the Medicare Part A deductible, as well as the per-day costs that would otherwise have to be paid for an extensive hospital stay.¹⁶ Medigap plans also pick up a large portion of the out-of-pocket costs that beneficiaries would otherwise have to pay for services covered by Medicare Part B.