| Internal medicine | 1,094 |
| Nurse practitioner | 630 |
| Physician assistant | 551 |
| Family practice | 527 |
| Physical therapist (private practice) | 455 |
| Anesthesiology | 449 |
| Emergency medicine | 392 |
| Psychiatry | 296 |
| Diagnostic Radiology | 240 |
| Obstetrics/gynecology | 232 |
| Optometrist | 215 |
| Ophthalmology | 175 |
| Chiropractic | 167 |
| Cardiology | 165 |
| Clinical psychologist | 157 |
| Neurology | 151 |
| General surgery | 138 |
| Dermatology | 131 |
| Gastroenterology | 124 |
| Orthopedic surgery | 122 |
| Licensed clinical social worker | 107 |
| Marriage and Family Therapist | 102 |
| Podiatry | 95 |
| Pathology | 94 |
| Mass Immunization Roster Billers | 88 |
| Hospitalist | 82 |
| Otolaryngology | 82 |
| Certified Registered Nurse Anesthetist (CRNA) | 81 |
| Physical medicine and rehabilitation | 75 |
| Urology | 70 |
| Hematology/oncology | 67 |
| Nephrology | 58 |
| Infectious disease | 53 |
| Endocrinology | 50 |
| Plastic and reconstructive surgery | 46 |
| Critical care (intensivists) | 46 |
| Rheumatology | 45 |
| Centralized Flu | 44 |
| Medical oncology | 42 |
| Pulmonary disease | 41 |
| Neurosurgery | 40 |
| Pediatric medicine | 38 |
| Occupational therapist (private practice) | 37 |
| Radiation oncology | 35 |
| Audiologist (billing independently) | 31 |
| Allergy/immunology | 28 |
| Vascular surgery | 26 |
| Interventional radiology | 26 |
| Ambulatory Surgical Center | 24 |
| Pain Management | 24 |
| Geriatric medicine | 23 |
| Pharmacy | 22 |
| General practice | 20 |
| Sleep Medicine | 17 |
| Hematology | 15 |
| Sports Medicine | 14 |
| Thoracic surgery | 14 |
| Hospice and Palliative Care | 13 |
| Unknown physician specialty | 13 |
| Registered Dietician/Nutrition Professional | 12 |
| Cardiac Electrophysiology | 12 |
| Mental Health Counselors | 12 |
| Clinical Laboratory (Billing Independently) | 12 |
| Interventional Cardiology | 11 |
| Certified clinical nurse specialist | 11 |
| Neuropsychiatry | 11 |
| Gynecologist/oncologist | 11 |
| Cardiac surgery | 10 |
| Speech / language pathology | 9 |
| Nuclear medicine | 9 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 9 |
| Colorectal surgery (formerly proctology) | 8 |
| Certified nurse midwife | 7 |
| Hand surgery | 7 |
| Medical Genetics and Genomics | 6 |
| Psychologist (billing independently) | 5 |
| Hematopoietic Cell Transplantation and Cellular Therapy | 5 |
| Surgical oncology | 5 |
| Addiction medicine | 5 |
| Independent Diagnostic Testing Facility (IDTF) | 5 |
| Dentist | 5 |
| Micrographic Dermatologic Surgery | 3 |
| Interventional Pain Management (IPM) | 3 |
| Advanced Heart Failure and Transplant Cardiology | 2 |
| Oral surgery (dentists only) | 2 |
| Preventive medicine | 2 |
| Adult Congenital Heart Disease | 2 |
| General Psychiatry | 1 |
| Home Infusion Therapy Services | 1 |
| Opioid Treatment Program | 1 |
| Portable X-Ray Supplier (Billing Independently) | 1 |
| Medicare Diabetes Preventive Program | 1 |
| Unknown Provider | 1 |
| Maxillofacial surgery | 1 |