| Internal medicine | 716 |
| Nurse practitioner | 407 |
| Physician assistant | 335 |
| Family practice | 323 |
| Physical therapist (private practice) | 307 |
| Anesthesiology | 288 |
| Emergency medicine | 248 |
| Psychiatry | 180 |
| Diagnostic Radiology | 158 |
| Obstetrics/gynecology | 150 |
| Optometrist | 140 |
| Ophthalmology | 120 |
| Chiropractic | 117 |
| Clinical psychologist | 103 |
| Cardiology | 99 |
| Neurology | 93 |
| General surgery | 89 |
| Dermatology | 82 |
| Orthopedic surgery | 80 |
| Gastroenterology | 78 |
| Licensed clinical social worker | 72 |
| Podiatry | 63 |
| Pathology | 61 |
| Marriage and Family Therapist | 58 |
| Hospitalist | 57 |
| Mass Immunization Roster Billers | 57 |
| Certified Registered Nurse Anesthetist (CRNA) | 55 |
| Otolaryngology | 50 |
| Physical medicine and rehabilitation | 42 |
| Hematology/oncology | 42 |
| Urology | 40 |
| Infectious disease | 36 |
| Nephrology | 35 |
| Rheumatology | 34 |
| Plastic and reconstructive surgery | 32 |
| Endocrinology | 31 |
| Neurosurgery | 29 |
| Critical care (intensivists) | 27 |
| Centralized Flu | 26 |
| Pulmonary disease | 25 |
| Pediatric medicine | 24 |
| Allergy/immunology | 22 |
| Medical oncology | 22 |
| Radiation oncology | 22 |
| Audiologist (billing independently) | 21 |
| Occupational therapist (private practice) | 21 |
| Vascular surgery | 19 |
| Ambulatory Surgical Center | 18 |
| Pharmacy | 17 |
| Geriatric medicine | 15 |
| Interventional radiology | 14 |
| General practice | 14 |
| Sleep Medicine | 11 |
| Pain Management | 11 |
| Registered Dietician/Nutrition Professional | 10 |
| Hematology | 9 |
| Cardiac surgery | 9 |
| Gynecologist/oncologist | 9 |
| Certified clinical nurse specialist | 8 |
| Hospice and Palliative Care | 8 |
| Cardiac Electrophysiology | 8 |
| Unknown physician specialty | 8 |
| Colorectal surgery (formerly proctology) | 7 |
| Sports Medicine | 7 |
| Neuropsychiatry | 7 |
| Thoracic surgery | 7 |
| Mental Health Counselors | 7 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 6 |
| Interventional Cardiology | 5 |
| Certified nurse midwife | 5 |
| Hematopoietic Cell Transplantation and Cellular Therapy | 5 |
| Medical Genetics and Genomics | 5 |
| Clinical Laboratory (Billing Independently) | 5 |
| Psychologist (billing independently) | 4 |
| Speech / language pathology | 4 |
| Nuclear medicine | 4 |
| Independent Diagnostic Testing Facility (IDTF) | 4 |
| Dentist | 3 |
| Hand surgery | 3 |
| Micrographic Dermatologic Surgery | 3 |
| Surgical oncology | 3 |
| Addiction medicine | 3 |
| Interventional Pain Management (IPM) | 3 |
| Oral surgery (dentists only) | 2 |
| Preventive medicine | 2 |
| General Psychiatry | 1 |
| Advanced Heart Failure and Transplant Cardiology | 1 |
| Home Infusion Therapy Services | 1 |
| Opioid Treatment Program | 1 |
| Portable X-Ray Supplier (Billing Independently) | 1 |
| Medicare Diabetes Preventive Program | 1 |