| Nurse practitioner | 341 |
| Physician assistant | 195 |
| Certified Registered Nurse Anesthetist (CRNA) | 175 |
| Internal medicine | 156 |
| Diagnostic Radiology | 136 |
| Anesthesiology | 105 |
| Cardiology | 92 |
| Physical therapist (private practice) | 90 |
| Family practice | 85 |
| Neurology | 71 |
| Gastroenterology | 68 |
| Pathology | 61 |
| Psychiatry | 51 |
| Licensed clinical social worker | 49 |
| Pulmonary disease | 47 |
| Medical oncology | 42 |
| Emergency medicine | 42 |
| Hospitalist | 38 |
| Dermatology | 38 |
| Orthopedic surgery | 38 |
| Physical medicine and rehabilitation | 38 |
| Ophthalmology | 37 |
| Mental Health Counselors | 32 |
| Hematology | 32 |
| Chiropractic | 30 |
| Clinical psychologist | 27 |
| General surgery | 26 |
| Nephrology | 26 |
| Hematology/oncology | 26 |
| Obstetrics/gynecology | 26 |
| Optometrist | 23 |
| Endocrinology | 23 |
| Rheumatology | 20 |
| Otolaryngology | 19 |
| Radiation oncology | 19 |
| Infectious disease | 18 |
| Occupational therapist (private practice) | 18 |
| Audiologist (billing independently) | 17 |
| Registered Dietician/Nutrition Professional | 15 |
| Mass Immunization Roster Billers | 15 |
| Hospice and Palliative Care | 12 |
| Geriatric medicine | 11 |
| Urology | 11 |
| Advanced Heart Failure and Transplant Cardiology | 11 |
| Neurosurgery | 10 |
| Plastic and reconstructive surgery | 10 |
| Certified clinical nurse specialist | 9 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 8 |
| Speech / language pathology | 8 |
| Epileptologists | 8 |
| Allergy/immunology | 8 |
| Marriage and Family Therapist | 8 |
| Cardiac Electrophysiology | 6 |
| Interventional Pain Management (IPM) | 6 |
| Pain Management | 6 |
| Interventional radiology | 6 |
| Pediatric medicine | 6 |
| Sleep Medicine | 6 |
| Micrographic Dermatologic Surgery | 6 |
| Hand surgery | 5 |
| Podiatry | 5 |
| Colorectal surgery (formerly proctology) | 4 |
| Vascular surgery | 4 |
| Sports Medicine | 4 |
| Maxillofacial surgery | 4 |
| Certified nurse midwife | 4 |
| Centralized Flu | 3 |
| Gynecologist/oncologist | 3 |
| Thoracic surgery | 2 |
| Nuclear medicine | 2 |
| Oral surgery (dentists only) | 2 |
| Critical care (intensivists) | 2 |
| Cardiac surgery | 2 |
| Pharmacy | 2 |
| Medical Genetics and Genomics | 2 |
| Clinical Laboratory (Billing Independently) | 1 |
| Undersea and Hyperbaric Medicine | 1 |
| Interventional Cardiology | 1 |
| General practice | 1 |
| Preventive medicine | 1 |
| Opioid Treatment Program | 1 |