Understanding Medicare Part A and Part B Coverage

What Medicare Part A and Part B Cover: The Basic Framework

Medicare Part A and Part B form the foundation of original Medicare, a federal health insurance program available to people age 65 and older, some younger people with disabilities, and people with end-stage renal disease. Understanding what these two parts cover helps you know what types of medical services the program may pay for and what costs might fall to you.

Get Your Free iPhone Screen Repair Guide →

Part A primarily covers inpatient hospital care. This includes hospital stays, skilled nursing facility stays, hospice care, and some home health services. When you're admitted to a hospital as an inpatient (meaning you stay overnight for treatment), Part A generally covers your room, meals, standard nursing care, and necessary medical supplies and equipment during your stay. Part A does not cover outpatient hospital services, which are handled differently.

Part B covers outpatient medical services and supplies. This includes visits to doctors' offices, outpatient hospital services, diagnostic tests like blood work and imaging, physical therapy, mental health services, and durable medical equipment such as wheelchairs or oxygen tanks. Part B also covers preventive services designed to catch health problems early, including annual wellness visits, cancer screenings, and vaccines.

According to 2024 data, approximately 45 million people were enrolled in Medicare, with the vast majority using Original Medicare (Part A and B) as their foundation for coverage. The program operates on a fee-for-service model, meaning Medicare pays healthcare providers based on the services delivered. This differs from Medicare Advantage plans (Part C), which use managed care networks with different rules and coverage structures.

A practical takeaway: Create a simple two-column chart on your own computer or paper listing "Part A Covers" and "Part B Covers" based on what you read here. When you receive medical bills or statements, refer to this chart to understand which part of Medicare should have been involved in payment.

Part A Coverage in Detail: Hospital and Facility-Based Care

Medicare Part A coverage centers on inpatient care, meaning you are formally admitted to a facility and stay overnight. The coverage rules and costs depend on the type of facility and the length of your stay.

Learn About Affordable Dental Programs and Options →

For hospital inpatient care, Part A covers the full cost of your hospital room (whether it's a standard room or intensive care), meals, nursing services, medications given during your hospital stay, blood transfusions, and medical equipment and supplies used during treatment. If you need surgery while hospitalized, Part A covers the operating room, surgical instruments, and anesthesia. Part A also covers some limited preventive care items like vaccinations given during a hospital stay. However, Part A does not cover private rooms unless medically necessary, nor does it pay for personal comfort items like telephone service, television, or in-room movies.

Skilled nursing facility (SNF) care is another major Part A benefit. A SNF is not the same as a regular nursing home or assisted living facility; it's a facility that provides skilled nursing care and rehabilitation services. Part A covers SNF care only if you've been hospitalized for at least three days immediately before entering the SNF, and the SNF care must be for a condition related to your hospital stay or for a condition that arose during your hospital stay. Part A covers all covered services for the first 20 days of your SNF stay in a benefit period. Days 21 through 100 require you to pay a daily coinsurance amount (in 2024, this is $200 per day). After 100 days in a single benefit period, Part A coverage ends.

Home health services are covered by Part A when certain conditions are met. You must be homebound (meaning leaving home is medically contraindicated or requires substantial assistance), you must be under a doctor's care, and you must need skilled nursing care or physical/occupational therapy. The home health agency must be Medicare-certified. Part A covers the services of nurses, physical therapists, occupational therapists, and home health aides. Medical equipment like hospital beds or walkers may also be covered. Part A does not cover routine care like bathing for personal hygiene alone or housekeeping services.

Hospice care is covered by Part A for people with a terminal illness expected to live six months or less. Part A covers pain relief medications, comfort care, counseling, and services of the hospice team. You generally can continue with other Medicare benefits at the same time, though some exceptions apply.

A practical takeaway: Before entering a hospital or facility, ask the admission team whether your stay will be considered inpatient (overnight admission) or observation status. This distinction matters significantly for Part A coverage. Request written confirmation of your admission status, as observation status triggers different coverage rules and costs.

Part B Coverage in Detail: Doctor Visits and Outpatient Services

Medicare Part B covers services and supplies you typically receive outside a hospital setting. The scope of Part B is broad and covers many of the medical services most people use regularly.

Get Your Free Accessible Printing Guide →

Doctor visits represent the foundation of Part B coverage. This includes visits to your primary care physician, visits to specialists like cardiologists or dermatologists, and consultations with other healthcare professionals. Part B covers the physician's services whether the visit occurs in a medical office, your home, a hospital outpatient department, or a nursing facility. Part B also covers services provided by nurse practitioners, physician assistants, and other clinical professionals working under a doctor's supervision.

Diagnostic and laboratory services are extensively covered by Part B. This includes blood tests, urinalysis, imaging services like X-rays and ultrasounds, and more complex procedures like CT scans and MRI imaging. Part B covers electrocardiograms (EKGs), stress tests, and other diagnostic procedures that help doctors understand your health status and diagnose conditions. Part B also covers pathology services, meaning the analysis of tissue samples and biopsies.

Mental health services receive robust coverage under Part B. This includes visits to psychiatrists, psychologists, clinical social workers, and other mental health professionals. Part B covers treatment for depression, anxiety, substance use disorders, and other mental health conditions. The coverage extends to both individual therapy and group therapy sessions. In recent years, Medicare expanded mental health coverage by reducing cost-sharing for certain mental health services, recognizing the importance of behavioral health as part of overall medical care.

Physical therapy, occupational therapy, and speech-language pathology services are covered by Part B when medically necessary and ordered by a physician. These rehabilitative services help restore function after illness, injury, or surgery. Part B covers these services in various settings including outpatient clinics, hospitals, and some cases at home (though home-based therapy may involve different rules).

Durable medical equipment (DME) represents another significant Part B benefit. DME includes items like wheelchairs, walkers, canes, crutches, hospital beds, oxygen equipment, continuous positive airway pressure (CPAP) machines, and similar items that serve a medical purpose and can withstand repeated use. Part B covers 80 percent of the Medicare-approved amount for DME after you meet your annual deductible, leaving you responsible for the remaining 20 percent coinsurance.

Preventive services covered by Part B include annual wellness visits, colorectal cancer screening, breast cancer screening, cardiovascular screening, diabetes screening, osteoporosis screening, pneumonia vaccination, flu vaccination, and COVID-19 vaccination. Part B covers these preventive services at no cost-sharing (no copayment, coinsurance, or deductible) when provided by a Medicare-participating provider and delivered according to Medicare guidelines.

Ambulance services are covered by Part B when transportation by a standard vehicle would be unsafe or when you have a medical condition requiring specialized transport. Part B covers ground ambulances, and in some cases, air ambulances.

A practical takeaway: Review the preventive services covered by Part B and consider scheduling annual visits and screenings. Since Part B covers these at no cost-sharing when delivered correctly, taking advantage of this coverage is financially smart and supports early detection of health problems.

Understanding Your Costs: Deductibles, Coinsurance, and Copayments

While Part A and Part B cover many services, you share in the costs through several mechanisms. Understanding these cost-sharing structures helps you plan for out-of-pocket expenses and avoid surprises when you receive bills.

Learn About Kinesiology and How It Works →

Part A involves different cost-sharing depending on the type of care. For inpatient hospital care, you pay a deductible per benefit period (in 2024, this is $1,632). A benefit period starts when you enter a hospital and ends 60 days after you've left both