| Nurse practitioner | 355 |
| Physician assistant | 243 |
| Internal medicine | 136 |
| Anesthesiology | 132 |
| Family practice | 113 |
| Emergency medicine | 105 |
| Certified Registered Nurse Anesthetist (CRNA) | 77 |
| Diagnostic Radiology | 74 |
| Neurology | 58 |
| Hospitalist | 53 |
| Gastroenterology | 48 |
| Psychiatry | 48 |
| Clinical psychologist | 48 |
| Physical therapist (private practice) | 47 |
| Anesthesiologist Assistant | 46 |
| Pathology | 40 |
| Obstetrics/gynecology | 40 |
| Chiropractic | 39 |
| Ophthalmology | 39 |
| Licensed clinical social worker | 38 |
| General surgery | 35 |
| Orthopedic surgery | 34 |
| Optometrist | 28 |
| Infectious disease | 27 |
| Mental Health Counselors | 27 |
| Dermatology | 27 |
| Centralized Flu | 26 |
| Mass Immunization Roster Billers | 26 |
| Nephrology | 26 |
| Cardiology | 24 |
| Urology | 24 |
| Pulmonary disease | 23 |
| Critical care (intensivists) | 22 |
| Physical medicine and rehabilitation | 22 |
| Interventional Cardiology | 21 |
| Endocrinology | 20 |
| Neurosurgery | 18 |
| Otolaryngology | 17 |
| Rheumatology | 15 |
| Certified nurse midwife | 15 |
| Medical oncology | 15 |
| Hematology/oncology | 15 |
| Pediatric medicine | 15 |
| Occupational therapist (private practice) | 12 |
| Podiatry | 11 |
| Hematology | 10 |
| Vascular surgery | 9 |
| Thoracic surgery | 9 |
| Radiation oncology | 9 |
| Cardiac Electrophysiology | 9 |
| Interventional radiology | 9 |
| Plastic and reconstructive surgery | 7 |
| Oral surgery (dentists only) | 7 |
| Audiologist (billing independently) | 7 |
| Ambulatory Surgical Center | 7 |
| General practice | 7 |
| Advanced Heart Failure and Transplant Cardiology | 6 |
| Marriage and Family Therapist | 6 |
| Registered Dietician/Nutrition Professional | 6 |
| Geriatric medicine | 6 |
| Sports Medicine | 5 |
| Independent Diagnostic Testing Facility (IDTF) | 4 |
| Hand surgery | 4 |
| Allergy/immunology | 4 |
| Hospice and Palliative Care | 4 |
| Pain Management | 3 |
| Surgical oncology | 3 |
| Speech / language pathology | 3 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 3 |
| Interventional Pain Management (IPM) | 3 |
| Micrographic Dermatologic Surgery | 2 |
| Psychologist (billing independently) | 2 |
| Opioid Treatment Program | 2 |
| Gynecologist/oncologist | 2 |
| Sleep Medicine | 2 |
| Addiction medicine | 2 |
| Pharmacy | 1 |
| Oral and Maxillofacial Radiology | 1 |
| Neuropsychiatry | 1 |
| Preventive medicine | 1 |
| Portable X-Ray Supplier (Billing Independently) | 1 |
| All other suppliers, e.g., Drug Stores | 1 |
| Colorectal surgery (formerly proctology) | 1 |
| Clinical Laboratory (Billing Independently) | 1 |
| Osteopathic manipulative therapy | 1 |
| Maxillofacial surgery | 1 |