| Physician assistant | 320 |
| Internal medicine | 312 |
| Nurse practitioner | 291 |
| Licensed clinical social worker | 217 |
| Family practice | 177 |
| Certified Registered Nurse Anesthetist (CRNA) | 165 |
| Physical therapist (private practice) | 146 |
| Emergency medicine | 113 |
| Clinical psychologist | 89 |
| Psychiatry | 86 |
| Anesthesiology | 78 |
| Diagnostic Radiology | 73 |
| Obstetrics/gynecology | 68 |
| Chiropractic | 65 |
| Ophthalmology | 52 |
| Neurology | 47 |
| General surgery | 42 |
| Gastroenterology | 41 |
| Cardiology | 40 |
| Hospitalist | 37 |
| Optometrist | 37 |
| Mental Health Counselors | 36 |
| Pathology | 35 |
| Occupational therapist (private practice) | 34 |
| Physical medicine and rehabilitation | 34 |
| Dermatology | 33 |
| Mass Immunization Roster Billers | 32 |
| Urology | 31 |
| Orthopedic surgery | 29 |
| Endocrinology | 27 |
| Geriatric medicine | 27 |
| Pulmonary disease | 21 |
| Podiatry | 20 |
| Otolaryngology | 16 |
| Pediatric medicine | 14 |
| Rheumatology | 14 |
| Audiologist (billing independently) | 13 |
| Nephrology | 13 |
| Allergy/immunology | 13 |
| Cardiac Electrophysiology | 11 |
| Speech / language pathology | 11 |
| Hematology/oncology | 11 |
| Hospice and Palliative Care | 10 |
| Certified nurse midwife | 10 |
| Infectious disease | 10 |
| Neurosurgery | 9 |
| Sleep Medicine | 8 |
| Radiation oncology | 7 |
| Interventional Pain Management (IPM) | 7 |
| Epileptologists | 7 |
| Interventional radiology | 6 |
| Plastic and reconstructive surgery | 6 |
| Critical care (intensivists) | 6 |
| Centralized Flu | 5 |
| Thoracic surgery | 5 |
| Interventional Cardiology | 5 |
| Sports Medicine | 5 |
| Hematology | 5 |
| Hand surgery | 5 |
| Pharmacy | 4 |
| Micrographic Dermatologic Surgery | 4 |
| Vascular surgery | 4 |
| Medical oncology | 3 |
| Registered Dietician/Nutrition Professional | 3 |
| Pain Management | 3 |
| Colorectal surgery (formerly proctology) | 3 |
| Addiction medicine | 3 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 3 |
| Advanced Heart Failure and Transplant Cardiology | 2 |
| Gynecologist/oncologist | 2 |
| General Psychiatry | 2 |
| Maxillofacial surgery | 2 |
| Medicare Diabetes Preventive Program | 1 |
| Ambulatory Surgical Center | 1 |
| Opioid Treatment Program | 1 |
| Oral surgery (dentists only) | 1 |
| Osteopathic manipulative therapy | 1 |
| Medical Genetics and Genomics | 1 |
| Cardiac surgery | 1 |
| Nuclear medicine | 1 |