Medicare Part B is the portion of Medicare that covers both medically necessary services and preventive services. Medically necessary services include services and supplies needed to diagnose or treat a person's medical condition. Preventive services include health care that either prevents illness or detects it at an early stage.
As of 2014, the average monthly premium for Medicare Part B is $104.90 per month, and the deductible is $147 per year. Some individuals with higher incomes pay more for their Part B premium. In addition, certain limits are in place on coverage for occupational therapy, physical therapy and speech language pathology services as of 2014.