| Internal medicine | 700 |
| Nurse practitioner | 521 |
| Family practice | 294 |
| Physician assistant | 264 |
| Anesthesiology | 237 |
| Emergency medicine | 231 |
| Physical therapist (private practice) | 194 |
| Psychiatry | 193 |
| Clinical psychologist | 164 |
| Diagnostic Radiology | 164 |
| Obstetrics/gynecology | 155 |
| Hospitalist | 152 |
| Licensed clinical social worker | 134 |
| Neurology | 127 |
| Ophthalmology | 99 |
| Optometrist | 98 |
| Marriage and Family Therapist | 98 |
| Orthopedic surgery | 94 |
| Cardiology | 94 |
| Dermatology | 89 |
| Certified Registered Nurse Anesthetist (CRNA) | 83 |
| Chiropractic | 82 |
| Pathology | 75 |
| General surgery | 66 |
| Otolaryngology | 64 |
| Infectious disease | 62 |
| Gastroenterology | 56 |
| Podiatry | 51 |
| Pulmonary disease | 51 |
| Urology | 49 |
| Nephrology | 44 |
| Centralized Flu | 42 |
| Physical medicine and rehabilitation | 41 |
| Hematology/oncology | 41 |
| Pediatric medicine | 37 |
| Endocrinology | 31 |
| Mass Immunization Roster Billers | 30 |
| Rheumatology | 27 |
| Vascular surgery | 27 |
| Plastic and reconstructive surgery | 26 |
| Radiation oncology | 26 |
| Critical care (intensivists) | 26 |
| Geriatric medicine | 23 |
| Audiologist (billing independently) | 20 |
| Allergy/immunology | 20 |
| Medical oncology | 19 |
| Neurosurgery | 19 |
| Hospice and Palliative Care | 18 |
| Ambulatory Surgical Center | 17 |
| Occupational therapist (private practice) | 16 |
| Speech / language pathology | 15 |
| Registered Dietician/Nutrition Professional | 12 |
| Interventional Cardiology | 11 |
| Mental Health Counselors | 11 |
| Thoracic surgery | 11 |
| Certified nurse midwife | 11 |
| Pain Management | 9 |
| Interventional radiology | 8 |
| Sports Medicine | 8 |
| Surgical oncology | 7 |
| Cardiac Electrophysiology | 7 |
| Advanced Heart Failure and Transplant Cardiology | 7 |
| Hand surgery | 7 |
| Colorectal surgery (formerly proctology) | 6 |
| Interventional Pain Management (IPM) | 6 |
| General practice | 5 |
| Sleep Medicine | 5 |
| Osteopathic manipulative therapy | 4 |
| Oral surgery (dentists only) | 4 |
| Preventive medicine | 4 |
| Hematology | 4 |
| Nuclear medicine | 3 |
| Opioid Treatment Program | 3 |
| Maxillofacial surgery | 3 |
| Dentist | 3 |
| Psychologist (billing independently) | 3 |
| Micrographic Dermatologic Surgery | 2 |
| Clinical Laboratory (Billing Independently) | 2 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 2 |
| Unknown physician specialty | 2 |
| Gynecologist/oncologist | 1 |
| Adult Congenital Heart Disease | 1 |
| Medical Genetics and Genomics | 1 |
| Cardiac surgery | 1 |
| Independent Diagnostic Testing Facility (IDTF) | 1 |
| Medical Toxicology | 1 |
| Pharmacy | 1 |