| Nurse practitioner | 798 |
| Physician assistant | 378 |
| Internal medicine | 304 |
| Physical therapist (private practice) | 303 |
| Certified Registered Nurse Anesthetist (CRNA) | 279 |
| Family practice | 237 |
| Licensed clinical social worker | 201 |
| Mental Health Counselors | 169 |
| Emergency medicine | 163 |
| Obstetrics/gynecology | 118 |
| Anesthesiology | 112 |
| Optometrist | 100 |
| Diagnostic Radiology | 98 |
| Clinical psychologist | 92 |
| Mass Immunization Roster Billers | 73 |
| General surgery | 66 |
| Chiropractic | 57 |
| Orthopedic surgery | 55 |
| Psychiatry | 55 |
| Neurology | 53 |
| Occupational therapist (private practice) | 51 |
| Gastroenterology | 51 |
| Cardiology | 46 |
| Ophthalmology | 43 |
| Pathology | 37 |
| Podiatry | 35 |
| Hematology/oncology | 35 |
| Physical medicine and rehabilitation | 34 |
| Pulmonary disease | 33 |
| Dermatology | 32 |
| Otolaryngology | 32 |
| Centralized Flu | 31 |
| Audiologist (billing independently) | 31 |
| Hospitalist | 30 |
| Urology | 30 |
| Nephrology | 27 |
| Interventional Cardiology | 26 |
| Endocrinology | 22 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 20 |
| Registered Dietician/Nutrition Professional | 18 |
| Rheumatology | 17 |
| Radiation oncology | 17 |
| Interventional radiology | 16 |
| Cardiac Electrophysiology | 16 |
| Plastic and reconstructive surgery | 16 |
| Infectious disease | 15 |
| Speech / language pathology | 15 |
| Thoracic surgery | 12 |
| Allergy/immunology | 11 |
| Neurosurgery | 11 |
| Ambulatory Surgical Center | 11 |
| Geriatric medicine | 11 |
| Colorectal surgery (formerly proctology) | 10 |
| Pediatric medicine | 10 |
| Certified nurse midwife | 10 |
| Hand surgery | 9 |
| Marriage and Family Therapist | 8 |
| Pharmacy | 8 |
| Clinical Laboratory (Billing Independently) | 8 |
| Critical care (intensivists) | 7 |
| Medical oncology | 7 |
| Cardiac surgery | 6 |
| Certified clinical nurse specialist | 6 |
| Vascular surgery | 6 |
| Independent Diagnostic Testing Facility (IDTF) | 6 |
| Addiction medicine | 5 |
| General practice | 5 |
| Sports Medicine | 5 |
| Hospice and Palliative Care | 5 |
| Interventional Pain Management (IPM) | 5 |
| Opioid Treatment Program | 4 |
| Pain Management | 4 |
| Nuclear medicine | 4 |
| Advanced Heart Failure and Transplant Cardiology | 3 |
| Sleep Medicine | 3 |
| Gynecologist/oncologist | 3 |
| Surgical oncology | 3 |
| Public Health or Welfare Agencies (Federal, State, and local) | 3 |
| Neuropsychiatry | 2 |
| Oral surgery (dentists only) | 2 |
| Osteopathic manipulative therapy | 2 |
| Dentist | 2 |
| Hematopoietic Cell Transplantation and Cellular Therapy | 1 |
| Peripheral vascular disease | 1 |
| Medicare Diabetes Preventive Program | 1 |
| Preventive medicine | 1 |
| Micrographic Dermatologic Surgery | 1 |
| General Psychiatry | 1 |
| Psychologist (billing independently) | 1 |
| Portable X-Ray Supplier (Billing Independently) | 1 |
| Medical Toxicology | 1 |
| Maxillofacial surgery | 1 |