Any Medicare provider (e.g., hospital, skilled nursing facility, home health agency, outpatient physical therapy, comprehensive outpatient rehabilitation facility, end-stage renal disease facility, hospice, physician, non-physician provider, laboratory, supplier, etc.) providing medical services covered under Medicare Part B. Any organization, institution, or individual that provides health care services to Medicare beneficiaries. Physicians, ambulatory surgical centers and outpatient clinics are some of the providers of services covered under Medicare Part B.