| Internal medicine | 999 |
| Family practice | 862 |
| Nurse practitioner | 826 |
| Physician assistant | 624 |
| Emergency medicine | 581 |
| Physical therapist (private practice) | 540 |
| Anesthesiology | 357 |
| Diagnostic Radiology | 322 |
| Obstetrics/gynecology | 263 |
| Optometrist | 263 |
| Psychiatry | 256 |
| Certified Registered Nurse Anesthetist (CRNA) | 196 |
| Clinical psychologist | 190 |
| Licensed clinical social worker | 185 |
| Orthopedic surgery | 171 |
| Marriage and Family Therapist | 171 |
| Chiropractic | 165 |
| Hospitalist | 164 |
| General surgery | 162 |
| Mass Immunization Roster Billers | 149 |
| Neurology | 126 |
| Ophthalmology | 126 |
| Cardiology | 121 |
| Dermatology | 113 |
| Gastroenterology | 108 |
| Podiatry | 108 |
| Pathology | 101 |
| Otolaryngology | 80 |
| Hematology/oncology | 76 |
| Pulmonary disease | 72 |
| Pediatric medicine | 71 |
| Occupational therapist (private practice) | 69 |
| Urology | 65 |
| Physical medicine and rehabilitation | 65 |
| Nephrology | 65 |
| Critical care (intensivists) | 60 |
| Endocrinology | 45 |
| Rheumatology | 44 |
| Interventional radiology | 44 |
| Neurosurgery | 43 |
| Centralized Flu | 38 |
| Infectious disease | 36 |
| Audiologist (billing independently) | 35 |
| Registered Dietician/Nutrition Professional | 32 |
| Radiation oncology | 32 |
| Vascular surgery | 30 |
| Allergy/immunology | 29 |
| Speech / language pathology | 29 |
| Ambulatory Surgical Center | 27 |
| Plastic and reconstructive surgery | 26 |
| Pain Management | 20 |
| Interventional Cardiology | 20 |
| Mental Health Counselors | 19 |
| Pharmacy | 18 |
| Cardiac surgery | 16 |
| General practice | 16 |
| Medical oncology | 16 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 15 |
| Thoracic surgery | 14 |
| Hospice and Palliative Care | 14 |
| Surgical oncology | 14 |
| Unknown physician specialty | 14 |
| Colorectal surgery (formerly proctology) | 13 |
| Gynecologist/oncologist | 12 |
| Independent Diagnostic Testing Facility (IDTF) | 12 |
| Nuclear medicine | 11 |
| Epileptologists | 11 |
| Cardiac Electrophysiology | 10 |
| Sleep Medicine | 9 |
| Hand surgery | 9 |
| Geriatric medicine | 9 |
| Interventional Pain Management (IPM) | 8 |
| Advanced Heart Failure and Transplant Cardiology | 7 |
| Opioid Treatment Program | 7 |
| Certified nurse midwife | 7 |
| Sports Medicine | 6 |
| Clinical Laboratory (Billing Independently) | 6 |
| Osteopathic manipulative therapy | 5 |
| Preventive medicine | 4 |
| Medical Genetics and Genomics | 4 |
| Hematology | 4 |
| Oral surgery (dentists only) | 4 |
| Unknown Provider | 2 |
| Psychologist (billing independently) | 2 |
| Micrographic Dermatologic Surgery | 2 |
| Peripheral vascular disease | 2 |
| Home Infusion Therapy Services | 1 |
| Addiction medicine | 1 |
| Dentist | 1 |