| Physician assistant | 637 |
| Nurse practitioner | 541 |
| Licensed clinical social worker | 361 |
| Family practice | 297 |
| Physical therapist (private practice) | 260 |
| Internal medicine | 196 |
| Emergency medicine | 154 |
| Chiropractic | 147 |
| Mental Health Counselors | 120 |
| Optometrist | 116 |
| Anesthesiology | 108 |
| Diagnostic Radiology | 103 |
| Clinical psychologist | 100 |
| Obstetrics/gynecology | 88 |
| Certified Registered Nurse Anesthetist (CRNA) | 86 |
| Psychiatry | 81 |
| General surgery | 59 |
| Pediatric medicine | 54 |
| Orthopedic surgery | 53 |
| Neurology | 49 |
| Mass Immunization Roster Billers | 36 |
| Occupational therapist (private practice) | 35 |
| Physical medicine and rehabilitation | 34 |
| Gastroenterology | 32 |
| Ophthalmology | 32 |
| Audiologist (billing independently) | 29 |
| Cardiology | 29 |
| Dermatology | 28 |
| Pathology | 28 |
| Otolaryngology | 27 |
| Hospitalist | 27 |
| Pulmonary disease | 26 |
| Urology | 23 |
| Podiatry | 23 |
| Anesthesiologist Assistant | 21 |
| Centralized Flu | 21 |
| Hematology/oncology | 20 |
| Critical care (intensivists) | 13 |
| Radiation oncology | 12 |
| Speech / language pathology | 12 |
| Nephrology | 11 |
| Endocrinology | 11 |
| Pain Management | 11 |
| Allergy/immunology | 10 |
| Neurosurgery | 10 |
| Certified nurse midwife | 10 |
| Infectious disease | 10 |
| Vascular surgery | 10 |
| Plastic and reconstructive surgery | 9 |
| Interventional radiology | 9 |
| Ambulatory Surgical Center | 9 |
| Rheumatology | 9 |
| Colorectal surgery (formerly proctology) | 9 |
| Interventional Cardiology | 8 |
| Hospice and Palliative Care | 7 |
| Hand surgery | 7 |
| Sports Medicine | 7 |
| Geriatric medicine | 6 |
| Cardiac Electrophysiology | 6 |
| Sleep Medicine | 6 |
| Advanced Heart Failure and Transplant Cardiology | 5 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 5 |
| Registered Dietician/Nutrition Professional | 5 |
| Surgical oncology | 5 |
| General practice | 4 |
| Thoracic surgery | 4 |
| Cardiac surgery | 3 |
| Oral surgery (dentists only) | 3 |
| Osteopathic manipulative therapy | 3 |
| Pharmacy | 3 |
| Hematology | 3 |
| Medical oncology | 3 |
| Medical Genetics and Genomics | 2 |
| Maxillofacial surgery | 2 |
| Independent Diagnostic Testing Facility (IDTF) | 2 |
| Micrographic Dermatologic Surgery | 2 |
| Clinical Laboratory (Billing Independently) | 2 |
| Marriage and Family Therapist | 2 |
| Interventional Pain Management (IPM) | 2 |
| Hematopoietic Cell Transplantation and Cellular Therapy | 1 |
| Dentist | 1 |
| Radiation Therapy Centers | 1 |
| Addiction medicine | 1 |
| Undersea and Hyperbaric Medicine | 1 |
| Opioid Treatment Program | 1 |
| Gynecologist/oncologist | 1 |