Medicare Part B helps cover services from doctors and outpatient care that Medicare Part A does not cover. It also covers a number of other services not covered by Part A, such as home health care.
Medicare Part B covers two types of medical services. The first type is supplies and services that are medically necessary to treat a person's medical condition. These services must meet the standards of medical practice.
Medicare Part B also covers health care for illnesses, or care to help detect an illness at an early stage, when treatment is most beneficial. Those covered under Medicare Part B don't pay anything for most preventative services if the service is obtained from a health care provider who accepts Medicare.
Medicare Part B covers services such as ambulance service, clinical research, durable medical equipment service, inpatient care, outpatient care, partial hospitalization, mental health care, obtaining a second opinion before a surgery, and a limited amount of outpatient prescription drugs.
Medicare coverage is based on three things, including state and federal laws, national decisions regarding a treatment being covered, and local decisions by companies that process Medicare claims. These companies make the determination as to something being deemed medically necessary.