| Internal medicine | 816 |
| Family practice | 498 |
| Nurse practitioner | 483 |
| Emergency medicine | 409 |
| Physician assistant | 391 |
| Physical therapist (private practice) | 319 |
| Anesthesiology | 285 |
| Psychiatry | 230 |
| Obstetrics/gynecology | 215 |
| Clinical psychologist | 215 |
| Diagnostic Radiology | 208 |
| Optometrist | 191 |
| Chiropractic | 154 |
| Licensed clinical social worker | 141 |
| Ophthalmology | 134 |
| Marriage and Family Therapist | 130 |
| Orthopedic surgery | 119 |
| General surgery | 110 |
| Neurology | 103 |
| Podiatry | 99 |
| Hospitalist | 92 |
| Dermatology | 88 |
| Cardiology | 87 |
| Gastroenterology | 86 |
| Certified Registered Nurse Anesthetist (CRNA) | 75 |
| Mass Immunization Roster Billers | 73 |
| Hematology/oncology | 69 |
| Pathology | 61 |
| Otolaryngology | 59 |
| Nephrology | 57 |
| Pulmonary disease | 54 |
| Physical medicine and rehabilitation | 49 |
| Critical care (intensivists) | 48 |
| Urology | 47 |
| Endocrinology | 40 |
| Centralized Flu | 36 |
| Occupational therapist (private practice) | 34 |
| Infectious disease | 31 |
| Radiation oncology | 29 |
| Plastic and reconstructive surgery | 25 |
| Rheumatology | 25 |
| Pediatric medicine | 25 |
| Allergy/immunology | 24 |
| Neurosurgery | 24 |
| Ambulatory Surgical Center | 23 |
| Vascular surgery | 21 |
| Audiologist (billing independently) | 18 |
| Registered Dietician/Nutrition Professional | 18 |
| Hospice and Palliative Care | 18 |
| Speech / language pathology | 18 |
| General practice | 17 |
| Medical oncology | 16 |
| Interventional Cardiology | 14 |
| Interventional radiology | 13 |
| Nuclear medicine | 11 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 10 |
| Certified nurse midwife | 10 |
| Thoracic surgery | 9 |
| Hematology | 9 |
| Psychologist (billing independently) | 9 |
| Mental Health Counselors | 9 |
| Hand surgery | 8 |
| Pain Management | 8 |
| Sleep Medicine | 8 |
| Sports Medicine | 8 |
| Interventional Pain Management (IPM) | 7 |
| Independent Diagnostic Testing Facility (IDTF) | 7 |
| Colorectal surgery (formerly proctology) | 7 |
| Cardiac surgery | 7 |
| Pharmacy | 7 |
| Clinical Laboratory (Billing Independently) | 7 |
| Surgical oncology | 7 |
| Addiction medicine | 5 |
| Cardiac Electrophysiology | 5 |
| Oral surgery (dentists only) | 5 |
| Opioid Treatment Program | 4 |
| Gynecologist/oncologist | 3 |
| Geriatric medicine | 3 |
| Micrographic Dermatologic Surgery | 2 |
| Osteopathic manipulative therapy | 2 |
| Unknown physician specialty | 2 |
| General Psychiatry | 2 |
| Maxillofacial surgery | 2 |
| Home Infusion Therapy Services | 1 |
| Portable X-Ray Supplier (Billing Independently) | 1 |
| Neuropsychiatry | 1 |
| Dentist | 1 |
| Preventive medicine | 1 |
| Peripheral vascular disease | 1 |