| Nurse practitioner | 830 |
| Physician assistant | 580 |
| Family practice | 296 |
| Physical therapist (private practice) | 287 |
| Licensed clinical social worker | 255 |
| Certified Registered Nurse Anesthetist (CRNA) | 252 |
| Internal medicine | 245 |
| Emergency medicine | 206 |
| Mental Health Counselors | 195 |
| Anesthesiology | 123 |
| Optometrist | 121 |
| Hospitalist | 105 |
| Obstetrics/gynecology | 105 |
| Diagnostic Radiology | 99 |
| Chiropractic | 95 |
| Mass Immunization Roster Billers | 81 |
| General surgery | 81 |
| Clinical psychologist | 81 |
| Psychiatry | 75 |
| Orthopedic surgery | 65 |
| Neurology | 59 |
| Ophthalmology | 58 |
| Gastroenterology | 54 |
| Podiatry | 53 |
| Pulmonary disease | 51 |
| Dermatology | 45 |
| Occupational therapist (private practice) | 43 |
| Cardiology | 40 |
| Otolaryngology | 35 |
| Nephrology | 34 |
| Audiologist (billing independently) | 34 |
| Centralized Flu | 32 |
| Urology | 31 |
| Speech / language pathology | 31 |
| Physical medicine and rehabilitation | 29 |
| Hematology/oncology | 29 |
| Pathology | 28 |
| Certified nurse midwife | 27 |
| Infectious disease | 26 |
| Registered Dietician/Nutrition Professional | 25 |
| Endocrinology | 24 |
| Interventional Cardiology | 23 |
| Rheumatology | 23 |
| Neurosurgery | 22 |
| Critical care (intensivists) | 22 |
| Plastic and reconstructive surgery | 21 |
| Vascular surgery | 19 |
| Marriage and Family Therapist | 19 |
| Pharmacy | 17 |
| Radiation oncology | 16 |
| Thoracic surgery | 15 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 14 |
| Sports Medicine | 13 |
| Hand surgery | 10 |
| Ambulatory Surgical Center | 10 |
| Cardiac Electrophysiology | 10 |
| Pediatric medicine | 9 |
| Allergy/immunology | 9 |
| Interventional radiology | 8 |
| Pain Management | 8 |
| Opioid Treatment Program | 7 |
| Cardiac surgery | 7 |
| Hospice and Palliative Care | 6 |
| Sleep Medicine | 6 |
| General practice | 5 |
| Public Health or Welfare Agencies (Federal, State, and local) | 4 |
| Independent Diagnostic Testing Facility (IDTF) | 4 |
| Clinical Laboratory (Billing Independently) | 4 |
| Colorectal surgery (formerly proctology) | 4 |
| Medical oncology | 4 |
| Surgical oncology | 3 |
| Advanced Heart Failure and Transplant Cardiology | 3 |
| Gynecologist/oncologist | 3 |
| Interventional Pain Management (IPM) | 2 |
| Neuropsychiatry | 2 |
| Geriatric medicine | 2 |
| Micrographic Dermatologic Surgery | 2 |
| Home Infusion Therapy Services | 2 |
| Oral surgery (dentists only) | 2 |
| Nuclear medicine | 2 |
| Addiction medicine | 2 |
| Osteopathic manipulative therapy | 1 |
| Dentist | 1 |
| Certified clinical nurse specialist | 1 |
| Portable X-Ray Supplier (Billing Independently) | 1 |
| Preventive medicine | 1 |
| Psychologist (billing independently) | 1 |