| Internal medicine | 2,352 |
| Nurse practitioner | 2,130 |
| Family practice | 1,690 |
| Physical therapist (private practice) | 1,372 |
| Physician assistant | 1,311 |
| Anesthesiology | 999 |
| Emergency medicine | 973 |
| Diagnostic Radiology | 627 |
| Psychiatry | 599 |
| Clinical psychologist | 578 |
| Obstetrics/gynecology | 540 |
| Optometrist | 513 |
| Licensed clinical social worker | 502 |
| Ophthalmology | 451 |
| Hospitalist | 405 |
| Mass Immunization Roster Billers | 389 |
| Marriage and Family Therapist | 382 |
| Orthopedic surgery | 381 |
| Chiropractic | 370 |
| Neurology | 367 |
| General surgery | 360 |
| Cardiology | 349 |
| Podiatry | 322 |
| Dermatology | 320 |
| Certified Registered Nurse Anesthetist (CRNA) | 306 |
| Gastroenterology | 289 |
| Pathology | 252 |
| Urology | 200 |
| Pulmonary disease | 194 |
| Nephrology | 193 |
| Hematology/oncology | 189 |
| Otolaryngology | 185 |
| Occupational therapist (private practice) | 180 |
| Physical medicine and rehabilitation | 178 |
| General practice | 175 |
| Clinical Laboratory (Billing Independently) | 153 |
| Endocrinology | 148 |
| Infectious disease | 140 |
| Ambulatory Surgical Center | 136 |
| Pediatric medicine | 132 |
| Neurosurgery | 114 |
| Radiation oncology | 102 |
| Rheumatology | 102 |
| Interventional radiology | 100 |
| Speech / language pathology | 98 |
| Plastic and reconstructive surgery | 94 |
| Critical care (intensivists) | 91 |
| Pharmacy | 84 |
| Independent Diagnostic Testing Facility (IDTF) | 81 |
| Centralized Flu | 81 |
| Audiologist (billing independently) | 77 |
| Vascular surgery | 77 |
| Hospice and Palliative Care | 75 |
| Allergy/immunology | 72 |
| Medical oncology | 59 |
| Pain Management | 58 |
| Thoracic surgery | 57 |
| Geriatric medicine | 56 |
| Interventional Cardiology | 52 |
| Registered Dietician/Nutrition Professional | 50 |
| Surgical oncology | 46 |
| Colorectal surgery (formerly proctology) | 42 |
| Hematology | 37 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 36 |
| Mental Health Counselors | 35 |
| Cardiac Electrophysiology | 33 |
| Sports Medicine | 32 |
| Hand surgery | 28 |
| Psychologist (billing independently) | 26 |
| Oral surgery (dentists only) | 25 |
| Cardiac surgery | 24 |
| Nuclear medicine | 23 |
| Gynecologist/oncologist | 20 |
| Portable X-Ray Supplier (Billing Independently) | 19 |
| Advanced Heart Failure and Transplant Cardiology | 19 |
| Interventional Pain Management (IPM) | 17 |
| Opioid Treatment Program | 17 |
| Certified nurse midwife | 12 |
| Unknown physician specialty | 11 |
| Osteopathic manipulative therapy | 11 |
| Sleep Medicine | 10 |
| Dentist | 10 |
| Preventive medicine | 9 |
| Maxillofacial surgery | 9 |
| Medical Genetics and Genomics | 7 |
| Epileptologists | 6 |
| General Psychiatry | 6 |
| Neuropsychiatry | 6 |
| Addiction medicine | 5 |
| Unknown Provider | 4 |
| Home Infusion Therapy Services | 3 |
| Micrographic Dermatologic Surgery | 2 |
| Intensive Cardiac Rehabilitation | 1 |
| Hematopoietic Cell Transplantation and Cellular Therapy | 1 |
| Peripheral vascular disease | 1 |
| Medicare Diabetes Preventive Program | 1 |
| All other suppliers, e.g., Drug Stores | 1 |
| Adult Congenital Heart Disease | 1 |
| Orofacial Pain | 1 |
| Certified clinical nurse specialist | 1 |