In addition to doctor bills, Part B covers many other types of outpatient care. This includes care at an emergency room or clinic, X-rays, and laboratory work. Ambulance service is also covered, in an emergency or other situation -- such as hospital discharge -- when regular transportation is not medically advisable.

Part B covers medical equipment and supplies, including splints, braces, bandages, prosthetics, walkers, and remedial shoes. It also includes such equipment as glucose monitors, ventilators, and pacemakers, as well as wheelchairs and hospital beds. For any of this to be covered, however, it must be prescribed by a doctor.

Part B also covers physical and speech therapy, if prescribed and regularly reviewed by a doctor. The therapist or facility providing the care must be Medicare-certified. How much Medicare pays for this care is determined by where the care is provided.