| Physical therapist (private practice) | 764 |
| Internal medicine | 701 |
| Family practice | 663 |
| Nurse practitioner | 608 |
| Physician assistant | 599 |
| Anesthesiology | 398 |
| Emergency medicine | 251 |
| Optometrist | 247 |
| Chiropractic | 223 |
| Clinical psychologist | 198 |
| Diagnostic Radiology | 173 |
| Ophthalmology | 162 |
| Dermatology | 156 |
| Obstetrics/gynecology | 156 |
| Mass Immunization Roster Billers | 150 |
| Orthopedic surgery | 139 |
| Psychiatry | 134 |
| Licensed clinical social worker | 118 |
| Marriage and Family Therapist | 113 |
| General surgery | 108 |
| Neurology | 108 |
| Occupational therapist (private practice) | 96 |
| Hospitalist | 95 |
| Podiatry | 95 |
| Cardiology | 94 |
| Certified Registered Nurse Anesthetist (CRNA) | 88 |
| Gastroenterology | 87 |
| Hematology/oncology | 77 |
| Pediatric medicine | 74 |
| Pathology | 72 |
| Otolaryngology | 65 |
| Pulmonary disease | 61 |
| Urology | 61 |
| Ambulatory Surgical Center | 60 |
| Physical medicine and rehabilitation | 58 |
| Nephrology | 50 |
| Endocrinology | 50 |
| Plastic and reconstructive surgery | 38 |
| Allergy/immunology | 34 |
| Infectious disease | 34 |
| General practice | 33 |
| Audiologist (billing independently) | 32 |
| Radiation oncology | 30 |
| Neurosurgery | 29 |
| Rheumatology | 26 |
| Pharmacy | 26 |
| Centralized Flu | 25 |
| Pain Management | 23 |
| Interventional Cardiology | 22 |
| Interventional radiology | 21 |
| Vascular surgery | 21 |
| Critical care (intensivists) | 19 |
| Clinical Laboratory (Billing Independently) | 18 |
| Registered Dietician/Nutrition Professional | 16 |
| Cardiac Electrophysiology | 15 |
| Medical oncology | 13 |
| Certified nurse midwife | 13 |
| Hospice and Palliative Care | 12 |
| Independent Diagnostic Testing Facility (IDTF) | 12 |
| Hand surgery | 12 |
| Speech / language pathology | 11 |
| Colorectal surgery (formerly proctology) | 11 |
| Interventional Pain Management (IPM) | 10 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 10 |
| Sports Medicine | 9 |
| Thoracic surgery | 9 |
| Psychologist (billing independently) | 8 |
| Surgical oncology | 8 |
| Geriatric medicine | 7 |
| Cardiac surgery | 7 |
| Hematology | 7 |
| Gynecologist/oncologist | 7 |
| Mental Health Counselors | 5 |
| Osteopathic manipulative therapy | 5 |
| Nuclear medicine | 4 |
| Oral surgery (dentists only) | 4 |
| Dentist | 4 |
| Addiction medicine | 3 |
| Sleep Medicine | 3 |
| Opioid Treatment Program | 3 |
| Advanced Heart Failure and Transplant Cardiology | 2 |
| Preventive medicine | 2 |
| Medicare Diabetes Preventive Program | 1 |
| Certified clinical nurse specialist | 1 |
| General Psychiatry | 1 |
| Maxillofacial surgery | 1 |
| Micrographic Dermatologic Surgery | 1 |
| Unknown physician specialty | 1 |
| All other suppliers, e.g., Drug Stores | 1 |
| Portable X-Ray Supplier (Billing Independently) | 1 |