| Nurse practitioner | 848 |
| Physician assistant | 493 |
| Certified Registered Nurse Anesthetist (CRNA) | 346 |
| Internal medicine | 318 |
| Physical therapist (private practice) | 293 |
| Family practice | 273 |
| Licensed clinical social worker | 185 |
| Chiropractic | 178 |
| Emergency medicine | 154 |
| Mental Health Counselors | 129 |
| Optometrist | 109 |
| Anesthesiology | 103 |
| Diagnostic Radiology | 96 |
| Clinical psychologist | 89 |
| Occupational therapist (private practice) | 87 |
| Centralized Flu | 85 |
| Obstetrics/gynecology | 81 |
| Cardiology | 74 |
| Podiatry | 73 |
| Dermatology | 71 |
| Orthopedic surgery | 70 |
| Ophthalmology | 69 |
| Mass Immunization Roster Billers | 63 |
| Psychiatry | 62 |
| General surgery | 61 |
| Gastroenterology | 51 |
| Neurology | 36 |
| Otolaryngology | 36 |
| Audiologist (billing independently) | 35 |
| Pulmonary disease | 34 |
| Pathology | 33 |
| Hospitalist | 32 |
| Physical medicine and rehabilitation | 31 |
| Urology | 29 |
| Speech / language pathology | 27 |
| Ambulatory Surgical Center | 27 |
| Hematology/oncology | 26 |
| Infectious disease | 23 |
| Interventional Cardiology | 23 |
| Nephrology | 23 |
| Plastic and reconstructive surgery | 21 |
| Rheumatology | 19 |
| Endocrinology | 18 |
| Pediatric medicine | 17 |
| Pain Management | 16 |
| General practice | 16 |
| Medical oncology | 15 |
| Neurosurgery | 15 |
| Registered Dietician/Nutrition Professional | 14 |
| Interventional Pain Management (IPM) | 13 |
| Critical care (intensivists) | 12 |
| Allergy/immunology | 12 |
| Certified nurse midwife | 12 |
| Radiation oncology | 11 |
| Marriage and Family Therapist | 11 |
| Clinical Laboratory (Billing Independently) | 11 |
| Independent Diagnostic Testing Facility (IDTF) | 10 |
| Vascular surgery | 10 |
| Thoracic surgery | 10 |
| Anesthesiologist Assistant | 10 |
| Pharmacy | 10 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 9 |
| Cardiac Electrophysiology | 9 |
| Interventional radiology | 8 |
| Cardiac surgery | 7 |
| Hand surgery | 6 |
| Osteopathic manipulative therapy | 6 |
| Neuropsychiatry | 5 |
| Gynecologist/oncologist | 5 |
| Psychologist (billing independently) | 5 |
| Hospice and Palliative Care | 5 |
| Opioid Treatment Program | 5 |
| Colorectal surgery (formerly proctology) | 3 |
| Medical Genetics and Genomics | 2 |
| Micrographic Dermatologic Surgery | 2 |
| Geriatric medicine | 2 |
| Oral surgery (dentists only) | 2 |
| Portable X-Ray Supplier (Billing Independently) | 2 |
| Hematology | 1 |
| Surgical oncology | 1 |
| Nuclear medicine | 1 |
| Sleep Medicine | 1 |
| Addiction medicine | 1 |
| Maxillofacial surgery | 1 |