The Basic Coverage Medicare Provides

Medicare Part A covers hospital stays, skilled nursing facility care after a hospital stay, hospice care, and some home health services. Part B covers doctor visits, outpatient care, medical equipment, and preventive services like screenings and vaccines. Part D covers prescription drugs. Together, these three parts form what most people think of as "Medicare coverage," but each has limits on what it pays for and what you pay out of pocket.

Medicare does not cover everything a doctor might recommend. It covers services and supplies that Medicare considers medically necessary — meaning they treat or diagnose a condition, not prevent it in general. A colonoscopy to check for cancer is covered; a cosmetic procedure is not. A blood test your doctor orders is covered; a test you order yourself online is not. The distinction matters because you pay the full cost for anything Medicare does not cover.

Your coverage also depends on where you receive care. A hospital stay is covered under Part A; the same procedure done in an outpatient surgery center is covered under Part B, with different cost-sharing rules. A drug given to you in a hospital is covered under Part A; the same drug you take at home is covered under Part D. Understanding which part covers what helps you know what to expect to pay.

Key Takeaways

  • Part A covers hospital stays and skilled nursing care; Part B covers doctor visits and outpatient services; Part D covers prescription drugs taken at home.
  • Medicare covers services considered medically necessary to treat or diagnose a condition, not services for general wellness or prevention.
  • You pay different amounts depending on which part covers the service and whether you have met your deductible for that year.
  • Dental, vision, hearing aids, and long-term custodial care are not covered by Original Medicare, though some Medicare Advantage plans include them.
  • Your doctor must order a service for it to be covered; self-ordered tests and treatments are your responsibility to pay for.

What Part A Covers: Hospital and Skilled Nursing Care

Part A covers a hospital stay when you are admitted as an inpatient — meaning you stay overnight and the hospital admits you to a bed. It covers the room, meals, nursing care, and most hospital services and supplies. It does not cover a visit to the emergency room if you are not admitted, or an outpatient procedure done in the hospital's surgery center.

After a hospital stay, Part A covers up to 100 days in a skilled nursing facility if your doctor orders it and you meet Medicare's requirements. The facility must be a Medicare-certified nursing home, and you must have been in the hospital for at least three days first. Part A pays all costs for days 1 through 20; from day 21 to day 100, you pay a daily amount (this amount changes each year). After day 100, you pay all costs.

Part A also covers hospice care when a doctor says you have six months or less to live, and some home health services when you are homebound and a doctor orders skilled care — such as a nurse visit or physical therapy. It does not cover ongoing personal care at home, such as help with bathing or meals, unless it is part of a skilled nursing visit.

What Part B Covers: Doctor Visits and Outpatient Services

Part B covers visits to your doctor, whether in the office or by telehealth. It covers tests your doctor orders, such as blood work or imaging. It covers preventive services with no cost to you — including annual wellness visits, cancer screenings, cardiovascular screenings, and vaccines for flu, pneumonia, and shingles. It covers outpatient surgery, emergency room visits, and urgent care.

Part B covers medical equipment and supplies your doctor prescribes, such as a wheelchair, oxygen, a continuous positive airway pressure (CPAP) machine, or diabetic testing supplies. It covers mental health services, including therapy and psychiatric visits. It covers rehabilitation services like physical therapy and occupational therapy when medically necessary.

Part B does not cover routine dental care, eye exams for glasses or contacts, hearing aids, or routine foot care (though it covers foot care if you have diabetes). It does not cover cosmetic procedures, weight loss programs, or most acupuncture. You pay a monthly premium for Part B, a yearly deductible, and then 20 percent of the cost of most services after the deductible is met.

What Part D Covers: Prescription Drugs

Part D covers prescription drugs you take at home. Each Part D plan has a list of covered drugs called a formulary, and the drugs on that list change from year to year. Your plan may require you to try a cheaper drug first before covering a more expensive one, or it may require your doctor to get approval before filling a prescription.

You pay a monthly premium for Part D, a yearly deductible, and then a percentage or flat amount per prescription depending on which tier the drug is on. Tier 1 drugs (generics) usually cost less; Tier 4 or 5 drugs (brand-name or specialty drugs) usually cost more. Once you and your plan together spend a certain amount on drugs in a year, you enter the "coverage gap" — a range where you pay more out of pocket. After you spend enough to reach the out-of-pocket limit, your plan pays most costs for the rest of the year.

Part D does not cover drugs used in a hospital or nursing facility (those are covered under Part A), or drugs given in a doctor's office (those are covered under Part B). It does not cover over-the-counter drugs, vitamins, or supplements unless they are on your plan's formulary and your doctor prescribes them as a drug.

Services and Supplies Medicare Does Not Cover

Original Medicare does not cover dental care, including cleanings, fillings, root canals, or dentures. It does not cover routine eye exams, glasses, or contact lenses. It does not cover hearing aids or hearing exams for the purpose of fitting aids. These are the most common gaps people encounter.

Medicare does not cover long-term custodial care — meaning ongoing help with daily activities like bathing, dressing, or meals — whether at home or in a nursing home. It covers skilled nursing care (care that requires a nurse or therapist) for a limited time after a hospital stay, but not custodial care. Many people confuse these two and assume Medicare will pay for a nursing home; it will not, except for the first 100 days after a may have access to hospital stay.

Medicare does not cover routine foot care, weight loss programs, most acupuncture, or services and supplies not ordered by a doctor. It does not cover care received outside the United States, except in limited cases near the border. It does not cover experimental treatments or drugs not yet approved by the Food and Drug Administration.

How Your Out-of-Pocket Costs Work

For Part A, you pay a deductible for each hospital stay (the amount changes yearly). After you meet the deductible, Medicare pays all costs for days 1 through 60. From day 61 to day 90, you pay a daily amount. After day 90, you pay more per day. For skilled nursing care, you pay nothing for days 1 through 20, then a daily amount for days 21 through 100.

For Part B, you pay a monthly premium, a yearly deductible, and then 20 percent of the cost of most services. Preventive services covered under Part B have no cost to you once the deductible is met. If you see an out-of-network doctor who does not accept Medicare, you may pay more or the full cost.

For Part D, you pay a monthly premium, a yearly deductible, and then a copay or coinsurance per prescription. The amount you pay depends on the drug's tier and how much you and your plan have spent so far that year. Once you reach the out-of-pocket limit, your plan pays most costs for the rest of the year.

If you have a Medigap policy or Medicare Advantage plan, your out-of-pocket costs may be lower because these plans help pay the costs Medicare does not cover. The trade-off is a higher monthly premium.

When to Ask Your Doctor or Medicare

Ask your doctor whether a service or supply is covered before you receive it, especially if it is expensive or you are unsure. Your doctor can tell you whether Medicare is likely to cover it, and if not, whether you want to pay out of pocket. Ask whether there is a cheaper alternative that Medicare covers.

Call Medicare directly at 1-800-MEDICARE (1-800-633-4227) if you want to know whether a specific service is covered. Have your Medicare number ready and be specific about what you are asking about — for example, "Does Medicare cover a knee replacement?" rather than "Does Medicare cover surgery?" Medicare can also tell you what you will pay out of pocket.

If Medicare denies coverage for something your doctor recommended, you have the right to appeal. Your doctor's office can help you file an appeal and provide the medical reason why the service is necessary. Many appeals are successful, especially when your doctor explains why the service is medically necessary for your condition.

Frequently Asked Questions

Does Medicare cover preventive care like cancer screenings?

Yes. Part B covers preventive services with no cost to you, including mammograms, colonoscopies, blood pressure checks, cholesterol screening, and vaccines for flu, pneumonia, and shingles. Your doctor must order the service, and it must be done at a Medicare-certified facility. Screening for a symptom you already have is usually covered as a diagnostic test rather than prevention.

Will Medicare pay for a nursing home?

Medicare covers up to 100 days in a skilled nursing facility after a hospital stay of at least three days, but only if you need skilled care like nursing or therapy. It does not cover a regular nursing home stay for custodial care — help with daily activities. Long-term nursing home care is usually paid for by Medicaid, private insurance, or out of pocket. Ask the nursing home which days Medicare will cover before you admit a family member.

What happens if my doctor prescribes a drug that is not on my Part D plan's list?

You can ask your doctor to prescribe a different drug that is on the list, or you can pay out of pocket for the drug your doctor recommended. You can also ask your plan to make an exception and cover the drug — this is called a formulary exception. Your doctor must provide medical reasons why the other drugs would not work for you. The plan has 72 hours to decide.

Does Medicare cover telehealth visits?

Yes. Part B covers telehealth visits with your doctor or other providers, and you pay the same amount as an in-person visit. During the COVID-19 pandemic, Medicare expanded telehealth coverage, and most of those changes remain in place. Ask your doctor's office whether they offer telehealth appointments.

If I have a Medicare Advantage plan instead of Original Medicare, what is different?

Medicare Advantage plans are run by private insurance companies and cover all the services Original Medicare covers, usually with lower out-of-pocket costs. Many include dental, vision, or hearing coverage that Original Medicare does not. The trade-off is that you must use doctors and hospitals in the plan's network, and you may need approval from the plan before receiving certain services. Check your plan's coverage details each year, because they change.