| Nurse practitioner | 195 |
| Certified Registered Nurse Anesthetist (CRNA) | 88 |
| Physician assistant | 84 |
| Physical therapist (private practice) | 58 |
| Chiropractic | 53 |
| Licensed clinical social worker | 45 |
| Mental Health Counselors | 43 |
| Hospitalist | 41 |
| Family practice | 37 |
| Optometrist | 31 |
| Psychiatry | 31 |
| Emergency medicine | 24 |
| Internal medicine | 22 |
| Speech / language pathology | 20 |
| Clinical psychologist | 20 |
| Anesthesiology | 19 |
| Diagnostic Radiology | 17 |
| Neurology | 16 |
| Obstetrics/gynecology | 15 |
| General surgery | 15 |
| Occupational therapist (private practice) | 13 |
| Orthopedic surgery | 12 |
| Pathology | 12 |
| Ophthalmology | 11 |
| Mass Immunization Roster Billers | 11 |
| Cardiology | 10 |
| Dermatology | 8 |
| Audiologist (billing independently) | 7 |
| Hematology/oncology | 7 |
| Urology | 7 |
| Critical care (intensivists) | 7 |
| Plastic and reconstructive surgery | 7 |
| Neurosurgery | 6 |
| Hand surgery | 5 |
| Podiatry | 5 |
| Unknown physician specialty | 5 |
| Gastroenterology | 5 |
| Ambulatory Surgical Center | 5 |
| Pulmonary disease | 5 |
| Otolaryngology | 5 |
| Physical medicine and rehabilitation | 4 |
| Nephrology | 4 |
| Radiation oncology | 4 |
| Infectious disease | 4 |
| Pediatric medicine | 4 |
| Interventional Cardiology | 4 |
| Cardiac Electrophysiology | 4 |
| Interventional radiology | 3 |
| Cardiac surgery | 3 |
| Certified clinical nurse specialist | 3 |
| Sports Medicine | 3 |
| Certified nurse midwife | 3 |
| Marriage and Family Therapist | 3 |
| Endocrinology | 3 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 3 |
| Colorectal surgery (formerly proctology) | 2 |
| Oral surgery (dentists only) | 2 |
| Allergy/immunology | 2 |
| Vascular surgery | 2 |
| General practice | 2 |
| Rheumatology | 2 |
| Registered Dietician/Nutrition Professional | 2 |
| Independent Diagnostic Testing Facility (IDTF) | 2 |
| Pharmacy | 1 |
| Undersea and Hyperbaric Medicine | 1 |
| Gynecologist/oncologist | 1 |
| Opioid Treatment Program | 1 |
| Sleep Medicine | 1 |
| Hematology | 1 |
| Advanced Heart Failure and Transplant Cardiology | 1 |
| Maxillofacial surgery | 1 |
| Clinical Laboratory (Billing Independently) | 1 |
| Surgical oncology | 1 |
| Thoracic surgery | 1 |
| Preventive medicine | 1 |
| Portable X-Ray Supplier (Billing Independently) | 1 |
| Medical oncology | 1 |
| Pain Management | 1 |