| Physician assistant | 757 |
| Nurse practitioner | 666 |
| Internal medicine | 288 |
| Physical therapist (private practice) | 265 |
| Family practice | 187 |
| Licensed clinical social worker | 162 |
| Chiropractic | 126 |
| Certified Registered Nurse Anesthetist (CRNA) | 121 |
| Anesthesiology | 119 |
| Emergency medicine | 96 |
| Mass Immunization Roster Billers | 95 |
| Obstetrics/gynecology | 94 |
| Mental Health Counselors | 92 |
| Diagnostic Radiology | 85 |
| Optometrist | 64 |
| Psychiatry | 61 |
| General surgery | 57 |
| Ophthalmology | 53 |
| Orthopedic surgery | 52 |
| Cardiology | 50 |
| Clinical psychologist | 50 |
| Neurology | 47 |
| Pathology | 46 |
| Occupational therapist (private practice) | 46 |
| Audiologist (billing independently) | 42 |
| Podiatry | 38 |
| Gastroenterology | 27 |
| Hospitalist | 27 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 27 |
| Urology | 25 |
| Nephrology | 25 |
| Speech / language pathology | 24 |
| Neurosurgery | 22 |
| Pediatric medicine | 22 |
| Pulmonary disease | 21 |
| Registered Dietician/Nutrition Professional | 20 |
| Otolaryngology | 20 |
| Physical medicine and rehabilitation | 18 |
| Dermatology | 17 |
| Rheumatology | 16 |
| Vascular surgery | 15 |
| Centralized Flu | 15 |
| Endocrinology | 13 |
| Hematology/oncology | 13 |
| Medical oncology | 13 |
| Plastic and reconstructive surgery | 12 |
| Radiation oncology | 11 |
| Thoracic surgery | 11 |
| Pharmacy | 9 |
| Certified nurse midwife | 8 |
| Ambulatory Surgical Center | 8 |
| Pain Management | 7 |
| Infectious disease | 7 |
| Colorectal surgery (formerly proctology) | 7 |
| Hematology | 6 |
| Critical care (intensivists) | 6 |
| Hospice and Palliative Care | 6 |
| Clinical Laboratory (Billing Independently) | 6 |
| Allergy/immunology | 6 |
| Gynecologist/oncologist | 6 |
| Nuclear medicine | 5 |
| General practice | 4 |
| Sleep Medicine | 4 |
| Dentist | 4 |
| Surgical oncology | 4 |
| Addiction medicine | 3 |
| Maxillofacial surgery | 3 |
| Hand surgery | 3 |
| Cardiac Electrophysiology | 3 |
| Sports Medicine | 3 |
| Opioid Treatment Program | 3 |
| Interventional radiology | 3 |
| Interventional Cardiology | 2 |
| Certified clinical nurse specialist | 2 |
| Geriatric medicine | 2 |
| Oral surgery (dentists only) | 2 |
| Osteopathic manipulative therapy | 2 |
| Portable X-Ray Supplier (Billing Independently) | 1 |
| Medical Genetics and Genomics | 1 |
| Advanced Heart Failure and Transplant Cardiology | 1 |
| Cardiac surgery | 1 |
| Home Infusion Therapy Services | 1 |
| Micrographic Dermatologic Surgery | 1 |
| Undersea and Hyperbaric Medicine | 1 |