| Nurse practitioner | 129 |
| Physician assistant | 51 |
| Internal medicine | 38 |
| Physical therapist (private practice) | 34 |
| Licensed clinical social worker | 33 |
| Optometrist | 32 |
| Anesthesiology | 27 |
| Emergency medicine | 18 |
| Family practice | 17 |
| Chiropractic | 16 |
| Mental Health Counselors | 14 |
| Audiologist (billing independently) | 13 |
| Diagnostic Radiology | 12 |
| General surgery | 12 |
| Obstetrics/gynecology | 11 |
| Occupational therapist (private practice) | 11 |
| Orthopedic surgery | 8 |
| Psychiatry | 8 |
| Hospitalist | 8 |
| Mass Immunization Roster Billers | 7 |
| Ambulatory Surgical Center | 5 |
| Podiatry | 5 |
| Certified nurse midwife | 5 |
| Cardiology | 5 |
| Urology | 4 |
| Otolaryngology | 4 |
| Neurology | 4 |
| Pathology | 3 |
| Pharmacy | 3 |
| Hospice and Palliative Care | 3 |
| Ophthalmology | 3 |
| Gastroenterology | 3 |
| Pulmonary disease | 3 |
| Speech / language pathology | 3 |
| Clinical psychologist | 3 |
| Interventional Cardiology | 2 |
| Vascular surgery | 2 |
| Physical medicine and rehabilitation | 2 |
| Registered Dietician/Nutrition Professional | 2 |
| Single or Multispecialty Clinic or Group Practice | 2 |
| Rheumatology | 2 |
| Dermatology | 2 |
| Sports Medicine | 2 |
| Plastic and reconstructive surgery | 2 |
| Hematology/oncology | 2 |
| Marriage and Family Therapist | 2 |
| Certified clinical nurse specialist | 1 |
| Pediatric medicine | 1 |
| Maxillofacial surgery | 1 |
| Neurosurgery | 1 |
| Cardiac Electrophysiology | 1 |
| Radiation oncology | 1 |
| Endocrinology | 1 |
| Nephrology | 1 |
| Thoracic surgery | 1 |
| Independent Diagnostic Testing Facility (IDTF) | 1 |
| Certified Registered Nurse Anesthetist (CRNA) | 1 |
| Interventional Pain Management (IPM) | 1 |
| Hand surgery | 1 |
| Interventional radiology | 1 |
| Allergy/immunology | 1 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 1 |