| Physician assistant | 1,141 |
| Nurse practitioner | 1,032 |
| Internal medicine | 419 |
| Physical therapist (private practice) | 419 |
| Family practice | 283 |
| Licensed clinical social worker | 250 |
| Chiropractic | 198 |
| Anesthesiology | 178 |
| Certified Registered Nurse Anesthetist (CRNA) | 174 |
| Mass Immunization Roster Billers | 150 |
| Emergency medicine | 147 |
| Mental Health Counselors | 137 |
| Obstetrics/gynecology | 133 |
| Diagnostic Radiology | 128 |
| Optometrist | 104 |
| Psychiatry | 86 |
| Orthopedic surgery | 84 |
| General surgery | 80 |
| Clinical psychologist | 78 |
| Cardiology | 76 |
| Ophthalmology | 72 |
| Occupational therapist (private practice) | 72 |
| Neurology | 69 |
| Audiologist (billing independently) | 66 |
| Pathology | 64 |
| Podiatry | 54 |
| Gastroenterology | 45 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 44 |
| Urology | 37 |
| Hospitalist | 36 |
| Nephrology | 36 |
| Registered Dietician/Nutrition Professional | 35 |
| Speech / language pathology | 32 |
| Dermatology | 32 |
| Pulmonary disease | 31 |
| Neurosurgery | 30 |
| Pediatric medicine | 30 |
| Physical medicine and rehabilitation | 27 |
| Otolaryngology | 27 |
| Centralized Flu | 26 |
| Medical oncology | 25 |
| Hematology/oncology | 23 |
| Thoracic surgery | 21 |
| Endocrinology | 20 |
| Plastic and reconstructive surgery | 20 |
| Vascular surgery | 19 |
| Rheumatology | 18 |
| Infectious disease | 18 |
| Ambulatory Surgical Center | 17 |
| Radiation oncology | 14 |
| Pharmacy | 13 |
| Allergy/immunology | 13 |
| Colorectal surgery (formerly proctology) | 12 |
| Pain Management | 11 |
| Clinical Laboratory (Billing Independently) | 10 |
| Certified nurse midwife | 8 |
| Critical care (intensivists) | 8 |
| Nuclear medicine | 7 |
| Dentist | 7 |
| Hospice and Palliative Care | 7 |
| Oral surgery (dentists only) | 7 |
| Surgical oncology | 7 |
| Hematology | 6 |
| Cardiac Electrophysiology | 6 |
| Sports Medicine | 6 |
| Gynecologist/oncologist | 6 |
| Interventional radiology | 6 |
| Hand surgery | 5 |
| Opioid Treatment Program | 5 |
| General practice | 4 |
| Sleep Medicine | 4 |
| Addiction medicine | 3 |
| Maxillofacial surgery | 3 |
| Interventional Cardiology | 3 |
| Geriatric medicine | 3 |
| Osteopathic manipulative therapy | 3 |
| Undersea and Hyperbaric Medicine | 3 |
| Certified clinical nurse specialist | 2 |
| Micrographic Dermatologic Surgery | 2 |
| Marriage and Family Therapist | 2 |
| Portable X-Ray Supplier (Billing Independently) | 1 |
| Medical Genetics and Genomics | 1 |
| Advanced Heart Failure and Transplant Cardiology | 1 |
| Cardiac surgery | 1 |
| Home Infusion Therapy Services | 1 |
| Hematopoietic Cell Transplantation and Cellular Therapy | 1 |
| Independent Diagnostic Testing Facility (IDTF) | 1 |