| Internal medicine | 1,078 |
| Nurse practitioner | 820 |
| Family practice | 459 |
| Physician assistant | 401 |
| Anesthesiology | 387 |
| Emergency medicine | 360 |
| Physical therapist (private practice) | 316 |
| Psychiatry | 312 |
| Diagnostic Radiology | 255 |
| Obstetrics/gynecology | 250 |
| Clinical psychologist | 246 |
| Hospitalist | 219 |
| Neurology | 209 |
| Licensed clinical social worker | 199 |
| Optometrist | 166 |
| Ophthalmology | 154 |
| Dermatology | 150 |
| Cardiology | 149 |
| Marriage and Family Therapist | 147 |
| Orthopedic surgery | 131 |
| Certified Registered Nurse Anesthetist (CRNA) | 125 |
| Chiropractic | 120 |
| Pathology | 106 |
| General surgery | 103 |
| Gastroenterology | 102 |
| Otolaryngology | 95 |
| Infectious disease | 89 |
| Podiatry | 89 |
| Pulmonary disease | 85 |
| Hematology/oncology | 65 |
| Nephrology | 64 |
| Urology | 62 |
| Physical medicine and rehabilitation | 59 |
| Centralized Flu | 58 |
| Endocrinology | 57 |
| Pediatric medicine | 52 |
| Mass Immunization Roster Billers | 44 |
| Radiation oncology | 43 |
| Plastic and reconstructive surgery | 40 |
| Rheumatology | 38 |
| Geriatric medicine | 35 |
| Critical care (intensivists) | 33 |
| Audiologist (billing independently) | 32 |
| Vascular surgery | 31 |
| Allergy/immunology | 31 |
| Medical oncology | 29 |
| Neurosurgery | 29 |
| Hospice and Palliative Care | 25 |
| Occupational therapist (private practice) | 25 |
| Ambulatory Surgical Center | 24 |
| Interventional Cardiology | 18 |
| General practice | 17 |
| Registered Dietician/Nutrition Professional | 17 |
| Speech / language pathology | 16 |
| Mental Health Counselors | 15 |
| Cardiac Electrophysiology | 15 |
| Interventional radiology | 14 |
| Pain Management | 14 |
| Thoracic surgery | 12 |
| Hand surgery | 12 |
| Certified nurse midwife | 12 |
| Surgical oncology | 11 |
| Sports Medicine | 11 |
| Colorectal surgery (formerly proctology) | 10 |
| Interventional Pain Management (IPM) | 9 |
| Advanced Heart Failure and Transplant Cardiology | 8 |
| Oral surgery (dentists only) | 8 |
| Opioid Treatment Program | 7 |
| Osteopathic manipulative therapy | 7 |
| Preventive medicine | 6 |
| Sleep Medicine | 6 |
| Psychologist (billing independently) | 6 |
| Hematology | 6 |
| Clinical Laboratory (Billing Independently) | 6 |
| Nuclear medicine | 5 |
| Gynecologist/oncologist | 5 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 5 |
| Micrographic Dermatologic Surgery | 3 |
| Maxillofacial surgery | 3 |
| Dentist | 3 |
| Pharmacy | 3 |
| Unknown physician specialty | 3 |
| Adult Congenital Heart Disease | 2 |
| Cardiac surgery | 2 |
| Independent Diagnostic Testing Facility (IDTF) | 2 |
| Medical Genetics and Genomics | 1 |
| Medical Toxicology | 1 |