| Physician assistant | 509 |
| Nurse practitioner | 377 |
| Internal medicine | 211 |
| Physical therapist (private practice) | 201 |
| Certified Registered Nurse Anesthetist (CRNA) | 181 |
| Family practice | 166 |
| Chiropractic | 110 |
| Diagnostic Radiology | 108 |
| Emergency medicine | 98 |
| Hospitalist | 88 |
| Licensed clinical social worker | 87 |
| Mental Health Counselors | 86 |
| Mass Immunization Roster Billers | 83 |
| Optometrist | 82 |
| Anesthesiology | 69 |
| Podiatry | 68 |
| Psychiatry | 56 |
| Obstetrics/gynecology | 51 |
| General surgery | 48 |
| Neurology | 48 |
| Orthopedic surgery | 46 |
| Occupational therapist (private practice) | 45 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 45 |
| Clinical psychologist | 42 |
| Cardiology | 38 |
| Pathology | 37 |
| Gastroenterology | 32 |
| Ophthalmology | 28 |
| Otolaryngology | 25 |
| Hematology/oncology | 22 |
| Physical medicine and rehabilitation | 22 |
| Audiologist (billing independently) | 21 |
| Dermatology | 20 |
| Pediatric medicine | 16 |
| Pulmonary disease | 14 |
| Registered Dietician/Nutrition Professional | 14 |
| Neurosurgery | 14 |
| Urology | 14 |
| Nephrology | 14 |
| Critical care (intensivists) | 13 |
| Radiation oncology | 13 |
| Vascular surgery | 12 |
| Rheumatology | 12 |
| Ambulatory Surgical Center | 12 |
| Speech / language pathology | 11 |
| Infectious disease | 11 |
| Oral surgery (dentists only) | 10 |
| Endocrinology | 10 |
| Interventional Cardiology | 10 |
| Thoracic surgery | 9 |
| Certified nurse midwife | 9 |
| Interventional radiology | 8 |
| Pharmacy | 7 |
| Cardiac Electrophysiology | 7 |
| Colorectal surgery (formerly proctology) | 7 |
| Allergy/immunology | 7 |
| Medical oncology | 6 |
| Hospice and Palliative Care | 6 |
| General practice | 5 |
| Independent Diagnostic Testing Facility (IDTF) | 5 |
| Plastic and reconstructive surgery | 5 |
| Sports Medicine | 5 |
| Hematology | 5 |
| Addiction medicine | 4 |
| Centralized Flu | 4 |
| Pain Management | 3 |
| Opioid Treatment Program | 3 |
| Gynecologist/oncologist | 3 |
| Cardiac surgery | 3 |
| Clinical Laboratory (Billing Independently) | 3 |
| Dentist | 2 |
| Nuclear medicine | 2 |
| Sleep Medicine | 2 |
| Hand surgery | 2 |
| Marriage and Family Therapist | 2 |
| Hematopoietic Cell Transplantation and Cellular Therapy | 1 |
| Home Infusion Therapy Services | 1 |
| Interventional Pain Management (IPM) | 1 |
| Undersea and Hyperbaric Medicine | 1 |
| Advanced Heart Failure and Transplant Cardiology | 1 |
| Geriatric medicine | 1 |
| Psychologist (billing independently) | 1 |
| Portable X-Ray Supplier (Billing Independently) | 1 |
| Oral and Maxillofacial Pathology | 1 |
| Osteopathic manipulative therapy | 1 |