This U.S. industry comprises establishments of health practitioners having the degree of M.D. (Doctor of Medicine) or D.O. (Doctor of Osteopathy) primarily engaged in the independent practice of general or specialized medicine (except psychiatry or psychoanalysis) or surgery. These practitioners operate private or group practices in their own offices (e.g., centers, clinics) or in the facilities of others, such as hospitals or HMO medical centers.

• Acupuncturists' (MDs or DOs) offices (e.g., centers, clinics)
• Allergists' offices (e.g., centers, clinics)
• Anesthesiologists' offices (e.g., centers, clinics)
• Cardiologists' offices (e.g., centers, clinics)
• Clinical pathologists' offices (e.g., centers, clinics)
• Dermatologists' offices (e.g., centers, clinics)
• Doctors of osteopathy (DOs, except mental health) offices (e.g., centers, clinics)
• DOs' (doctors of osteopathy, except mental health) offices (e.g., centers, clinics)
• Family physicians' offices (e.g., centers, clinics)
• Forensic pathologists' offices
• Gastroenterologists' offices (e.g., centers, clinics)
• Gynecologists' offices (e.g., centers, clinics)
• Health screening services in physicians' offices
• Immunologists' offices (e.g., centers, clinics)
• Internists' offices (e.g., centers, clinics)
• MDs' (medical doctors, except mental health) offices (e.g., centers, clinics)
• Medical doctors' (MDs, except mental health) offices (e.g., centers, clinics)
• Neurologists' offices (e.g., centers, clinics)
• Neuropathologists' offices (e.g., centers, clinics)
• Obstetricians' offices (e.g., centers, clinics)
• Oncologists' offices (e.g., centers, clinics)
• Ophthalmologists' offices (e.g., centers, clinics)
• Orthopedic physicians' offices (e.g., centers, clinics)
• Orthopedic surgeons' offices (e.g., centers, clinics)
• Osteopathic physicians' (except mental health) offices (e.g., centers, clinics)
• Otolaryngologists' offices (e.g., centers, clinics)
• Pathologists' (except oral, speech, voice) offices (e.g., centers, clinics)
• Pathologists', forensic, offices (e.g., centers, clinics)
• Pathologists', neuropathological, offices (e.g., centers, clinics)
• Pathologists', surgical, offices (e.g., centers, clinics)
• Pediatricians' (except mental health) offices (e.g., centers, clinics)
• Physicians' (except mental health) offices (e.g., centers, clinics)
• Plastic surgeons' offices (e.g., centers, clinics)
• Proctologists' offices (e.g., centers, clinics)
• Pulmonary specialists' offices (e.g., centers, clinics)
• Radiologists' offices (e.g., centers, clinics)
• Surgeons' (except dental) offices (e.g., centers, clinics)
• Surgical pathologists' offices (e.g., centers, clinics)
• Urologists' offices (e.g., centers, clinics)
• Walk-in physicians' offices (e.g., centers, clinics)