Medicare is health insurance run by the federal government for people 65 and older

Medicare is a federal health insurance program that covers hospital care, doctor visits, prescription drugs, and preventive services. You become may be able to access at 65 if you are a U.S. citizen or permanent resident who has lived in the country for at least five years. You do not have to be retired to join — age 65 is the trigger, whether you are still working or not.

The program has four main parts, each covering different services. Part A covers hospital stays and some skilled nursing care. Part B covers doctor visits and outpatient care. Part D covers prescription drugs. Part C, called Medicare Advantage, is an alternative way to receive Parts A and B through a private insurance company. Most people pay a monthly premium for Part B and Part D, though Part A is usually free if you or your spouse paid Medicare taxes while working.

Key Takeaways

  • Medicare Part A covers inpatient hospital care, skilled nursing facilities, and some home health services after a hospital stay.
  • Medicare Part B covers doctor office visits, outpatient procedures, lab tests, imaging, and preventive care like cancer screenings and vaccines.
  • Medicare Part D is prescription drug coverage, and you must enroll during your initial enrollment window or pay a penalty if you join later.
  • Medicare does not cover dental, vision, hearing aids, or long-term custodial care in nursing homes, though some Medicare Advantage plans offer limited dental and vision benefits.
  • You pay deductibles, copayments, and coinsurance amounts that vary by service and by which part of Medicare you use.

What Medicare Part A covers

Part A covers inpatient hospital stays, meaning you are admitted to the hospital and stay overnight. It pays for your room, meals, nursing care, and most hospital services. It also covers skilled nursing facility care — a facility where you receive medical care and rehabilitation after a hospital stay, not a regular nursing home where you live long-term. Part A also covers some home health services if a doctor orders them after a hospital stay or skilled nursing facility stay.

Part A does not cover custodial care, which is help with daily activities like bathing, dressing, and eating when that is the only service you need. It also does not cover private duty nursing or a private room unless medically necessary. You pay a deductible for each hospital stay, and if your stay is longer than 60 days, you pay coinsurance for days 61 through 90.

What Medicare Part B covers

Part B covers doctor office visits, whether your doctor is in a hospital, clinic, or private practice. It pays for outpatient surgery, emergency room visits, lab tests, X-rays, imaging like CT scans and MRIs, and physical therapy. Part B also covers preventive services at no cost to you, including annual wellness visits, cancer screenings (mammograms, colonoscopies, Pap tests), cardiovascular screenings, bone density tests, diabetes screenings, and vaccines like flu shots and pneumonia vaccines.

Part B does not cover routine dental care, eye exams for glasses or contacts, hearing aids, or most routine foot care. It also does not cover cosmetic surgery or experimental treatments. You pay a monthly premium for Part B, a yearly deductible, and then 20 percent coinsurance for most services after the deductible is met.

What Medicare Part D covers

Part D is prescription drug coverage offered through private insurance companies approved by Medicare. It covers brand-name and generic drugs on a formulary — a list of covered medications that varies by plan. You choose a Part D plan during your initial enrollment window, which is usually the three months before you turn 65 through the three months after. If you do not enroll when you are first may be able to access and you do not have other creditable drug coverage, you pay a penalty for each month you delay.

Part D coverage has a structure: you pay a monthly premium, then a yearly deductible (the amount varies by plan), then you pay a copayment or coinsurance for each prescription until you reach a spending threshold called the donut hole. Once you reach that threshold, you pay a higher percentage until your out-of-pocket costs hit an annual maximum, after which the plan pays most of the cost. The exact amounts and thresholds change each year.

What Medicare does not cover

Medicare does not cover dental care, including cleanings, fillings, extractions, and 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 hearing aids. It does not cover long-term custodial care in a nursing home — the kind of care where you live in the facility and receive help with daily activities but not medical treatment.

Medicare also does not cover most routine foot care, acupuncture, massage therapy, or most chiropractic care. It does not cover weight loss programs, fertility treatment, or cosmetic surgery. If you need these services, you either pay out of pocket or purchase a supplemental insurance policy called Medigap, or you choose a Medicare Advantage plan that may offer some of these benefits as add-ons.

How costs work: deductibles, copayments, and coinsurance

Medicare costs have three main pieces. A deductible is the amount you pay before Medicare starts to pay. Part A has a deductible per hospital stay. Part B has an annual deductible that resets each year. Part D deductibles vary by plan. A copayment is a fixed dollar amount you pay for a specific service — for example, $15 for a doctor visit. Coinsurance is a percentage of the cost you pay after the deductible — for example, 20 percent of the cost of an MRI.

The amounts change each year. Part B typically has a higher deductible than Part A, and Part D deductibles and copayments vary widely by plan. If you have Original Medicare (Part A and Part B), you can purchase a Medigap policy to cover some or all of the deductibles and coinsurance you would otherwise pay. If you choose Medicare Advantage (Part C), your costs are usually lower upfront, but you may have a network of doctors you must use and may face higher costs if you use out-of-network providers.

Medicare Advantage as an alternative to Original Medicare

Medicare Advantage, also called Part C, is an alternative way to receive your Part A and Part B coverage. Instead of enrolling in Original Medicare, you enroll in a private insurance plan approved by Medicare. The plan must cover everything Original Medicare covers, but it can charge different deductibles, copayments, and coinsurance. Many Medicare Advantage plans include Part D drug coverage, dental benefits, vision benefits, or hearing aid coverage as add-ons.

The trade-off is that most Medicare Advantage plans use a network model — you must use doctors and hospitals in the plan's network, or you pay more or the plan does not cover the service at all. Some plans allow out-of-network care for emergencies. If you travel frequently or have doctors you want to keep, Original Medicare with a Medigap policy may be a better fit. You can switch between Original Medicare and Medicare Advantage during the annual enrollment period, which runs from October 15 to December 7 each year.

Frequently Asked Questions

Do I have to enroll in Medicare at 65?

You must enroll in Part A and Part B during your initial enrollment window — the three months before you turn 65, the month you turn 65, and the three months after. If you delay and do not have other health coverage, you may pay a penalty for as long as you have Medicare. If you are still working and have health coverage through your employer, you may be able to delay without penalty, but you should contact Medicare to confirm your situation.

What is the difference between Original Medicare and Medicare Advantage?

Original Medicare is fee-for-service coverage run by the federal government — you can see any doctor who accepts Medicare. Medicare Advantage is coverage through a private insurance company that must cover the same services but typically uses a network of doctors and may charge different costs. Medicare Advantage often includes drug coverage and extra benefits like dental, but Original Medicare does not.

Do I need Medigap insurance?

Medigap is optional supplemental insurance that covers some of the deductibles and coinsurance you pay under Original Medicare. If you choose Original Medicare, Medigap can lower your out-of-pocket costs. If you choose Medicare Advantage, you do not need Medigap because the plan's costs are already set. You can enroll in Medigap during your initial enrollment window or within six months of enrolling in Part B.

Can I change my Medicare plan after I enroll?

Yes, during the annual enrollment period from October 15 to December 7, you can switch between Original Medicare and Medicare Advantage, or switch from one Medicare Advantage plan to another. You can also make changes if you move to a new state or have a may have access to life event like losing other health coverage. Outside these windows, changes are limited.

Does Medicare cover vision and dental care?

Original Medicare does not cover routine vision exams, glasses, or dental care. Some Medicare Advantage plans include limited dental and vision benefits, though they usually have annual maximums and may not cover all services. If you need extensive dental or vision care, you may want to purchase standalone dental and vision insurance or choose a Medicare Advantage plan that includes these benefits.