| General practice | 831 |
| Internal medicine | 418 |
| Clinical Laboratory (Billing Independently) | 395 |
| Cardiology | 157 |
| Obstetrics/gynecology | 152 |
| Family practice | 151 |
| Ophthalmology | 146 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 136 |
| Gastroenterology | 118 |
| Chiropractic | 114 |
| Clinical psychologist | 114 |
| Diagnostic Radiology | 109 |
| Physical medicine and rehabilitation | 99 |
| General surgery | 99 |
| Physical therapist (private practice) | 98 |
| Psychiatry | 85 |
| Anesthesiology | 79 |
| Orthopedic surgery | 75 |
| Neurology | 71 |
| Nephrology | 68 |
| Pulmonary disease | 68 |
| Endocrinology | 66 |
| Dermatology | 63 |
| Urology | 59 |
| Optometrist | 57 |
| Centralized Flu | 54 |
| Hematology/oncology | 51 |
| Infectious disease | 50 |
| Pathology | 46 |
| Otolaryngology | 41 |
| Emergency medicine | 41 |
| Rheumatology | 35 |
| Audiologist (billing independently) | 32 |
| Podiatry | 29 |
| Registered Dietician/Nutrition Professional | 22 |
| Neurosurgery | 18 |
| Licensed clinical social worker | 18 |
| Mass Immunization Roster Billers | 17 |
| Allergy/immunology | 16 |
| Nuclear medicine | 16 |
| Interventional radiology | 13 |
| Geriatric medicine | 10 |
| Radiation oncology | 10 |
| Pediatric medicine | 10 |
| Ambulatory Surgical Center | 9 |
| Cardiac Electrophysiology | 9 |
| Vascular surgery | 9 |
| Independent Diagnostic Testing Facility (IDTF) | 9 |
| Plastic and reconstructive surgery | 9 |
| Interventional Pain Management (IPM) | 8 |
| Colorectal surgery (formerly proctology) | 7 |
| Speech / language pathology | 6 |
| Interventional Cardiology | 6 |
| Critical care (intensivists) | 5 |
| Pain Management | 5 |
| Hand surgery | 4 |
| Psychologist (billing independently) | 4 |
| Cardiac surgery | 4 |
| Gynecologist/oncologist | 4 |
| Maxillofacial surgery | 3 |
| Pharmacy | 3 |
| Occupational therapist (private practice) | 3 |
| Physician assistant | 2 |
| Hospice and Palliative Care | 2 |
| Sports Medicine | 2 |
| Surgical oncology | 2 |
| Nurse practitioner | 2 |
| Sleep Medicine | 1 |
| Oral surgery (dentists only) | 1 |
| Medical oncology | 1 |
| General Psychiatry | 1 |
| Advanced Heart Failure and Transplant Cardiology | 1 |
| Thoracic surgery | 1 |
| Hematology | 1 |