| Nurse practitioner | 507 |
| Physician assistant | 453 |
| Physical therapist (private practice) | 171 |
| Family practice | 171 |
| Licensed clinical social worker | 161 |
| Internal medicine | 144 |
| Certified Registered Nurse Anesthetist (CRNA) | 121 |
| Emergency medicine | 95 |
| Anesthesiology | 85 |
| Clinical psychologist | 81 |
| Chiropractic | 69 |
| Mass Immunization Roster Billers | 68 |
| Diagnostic Radiology | 66 |
| Mental Health Counselors | 64 |
| Obstetrics/gynecology | 54 |
| Ophthalmology | 54 |
| Psychiatry | 53 |
| Cardiology | 51 |
| General surgery | 47 |
| Orthopedic surgery | 46 |
| Gastroenterology | 36 |
| Optometrist | 35 |
| Neurology | 31 |
| Podiatry | 29 |
| Occupational therapist (private practice) | 28 |
| Pathology | 27 |
| Urology | 27 |
| Hospitalist | 27 |
| Audiologist (billing independently) | 27 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 26 |
| Pulmonary disease | 24 |
| Pediatric medicine | 24 |
| Otolaryngology | 23 |
| Registered Dietician/Nutrition Professional | 22 |
| Physical medicine and rehabilitation | 19 |
| Hematology/oncology | 18 |
| Nephrology | 17 |
| Endocrinology | 17 |
| Plastic and reconstructive surgery | 16 |
| Dermatology | 15 |
| Certified nurse midwife | 14 |
| Centralized Flu | 14 |
| Speech / language pathology | 13 |
| Vascular surgery | 12 |
| Neurosurgery | 11 |
| Medical oncology | 10 |
| Interventional Cardiology | 10 |
| Hand surgery | 9 |
| Critical care (intensivists) | 9 |
| Thoracic surgery | 9 |
| Infectious disease | 9 |
| Radiation oncology | 8 |
| Ambulatory Surgical Center | 7 |
| Cardiac Electrophysiology | 6 |
| Allergy/immunology | 6 |
| Rheumatology | 5 |
| Interventional radiology | 5 |
| Interventional Pain Management (IPM) | 5 |
| Colorectal surgery (formerly proctology) | 4 |
| Hospice and Palliative Care | 4 |
| Opioid Treatment Program | 4 |
| Geriatric medicine | 3 |
| Oral surgery (dentists only) | 2 |
| Pain Management | 2 |
| Addiction medicine | 2 |
| Clinical Laboratory (Billing Independently) | 2 |
| Pharmacy | 2 |
| Gynecologist/oncologist | 2 |
| Micrographic Dermatologic Surgery | 1 |
| Independent Diagnostic Testing Facility (IDTF) | 1 |
| Hematology | 1 |
| Sports Medicine | 1 |
| Medical Genetics and Genomics | 1 |
| Cardiac surgery | 1 |
| Medical Toxicology | 1 |
| Sleep Medicine | 1 |
| Nuclear medicine | 1 |
| Home Infusion Therapy Services | 1 |
| Surgical oncology | 1 |
| Intensive Cardiac Rehabilitation | 1 |
| Osteopathic manipulative therapy | 1 |
| General practice | 1 |
| Maxillofacial surgery | 1 |
| Preventive medicine | 1 |
| Portable X-Ray Supplier (Billing Independently) | 1 |