| Nurse practitioner | 507 |
| Internal medicine | 185 |
| Certified Registered Nurse Anesthetist (CRNA) | 154 |
| Family practice | 138 |
| Emergency medicine | 114 |
| Physical therapist (private practice) | 114 |
| Physician assistant | 102 |
| Anesthesiology | 83 |
| Obstetrics/gynecology | 78 |
| Mental Health Counselors | 73 |
| Diagnostic Radiology | 59 |
| Orthopedic surgery | 47 |
| General surgery | 46 |
| Optometrist | 40 |
| Psychiatry | 39 |
| Mass Immunization Roster Billers | 38 |
| Cardiology | 37 |
| Licensed clinical social worker | 34 |
| Podiatry | 30 |
| Nephrology | 27 |
| Ophthalmology | 25 |
| Centralized Flu | 25 |
| Pathology | 24 |
| Neurology | 22 |
| Gastroenterology | 22 |
| Chiropractic | 20 |
| Occupational therapist (private practice) | 18 |
| Pediatric medicine | 17 |
| Pulmonary disease | 17 |
| Anesthesiologist Assistant | 16 |
| Ambulatory Surgical Center | 15 |
| Clinical psychologist | 15 |
| Dermatology | 15 |
| Interventional Cardiology | 13 |
| Hematology/oncology | 13 |
| Otolaryngology | 12 |
| Urology | 12 |
| Infectious disease | 11 |
| Neurosurgery | 9 |
| Speech / language pathology | 9 |
| Audiologist (billing independently) | 8 |
| Physical medicine and rehabilitation | 8 |
| Interventional radiology | 7 |
| Endocrinology | 7 |
| Clinical Laboratory (Billing Independently) | 7 |
| Rheumatology | 7 |
| Plastic and reconstructive surgery | 6 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 6 |
| Hospitalist | 6 |
| Vascular surgery | 5 |
| Registered Dietician/Nutrition Professional | 5 |
| Critical care (intensivists) | 5 |
| Pain Management | 5 |
| General practice | 5 |
| Maxillofacial surgery | 4 |
| Colorectal surgery (formerly proctology) | 4 |
| Independent Diagnostic Testing Facility (IDTF) | 4 |
| Medical oncology | 4 |
| Allergy/immunology | 4 |
| Cardiac surgery | 4 |
| Marriage and Family Therapist | 3 |
| Dentist | 3 |
| Cardiac Electrophysiology | 3 |
| Oral surgery (dentists only) | 3 |
| Radiation oncology | 3 |
| Portable X-Ray Supplier (Billing Independently) | 2 |
| Gynecologist/oncologist | 2 |
| Interventional Pain Management (IPM) | 2 |
| Certified clinical nurse specialist | 2 |
| Sleep Medicine | 2 |
| Osteopathic manipulative therapy | 1 |
| Pharmacy | 1 |
| Hand surgery | 1 |
| Single or Multispecialty Clinic or Group Practice | 1 |
| Opioid Treatment Program | 1 |
| Surgical oncology | 1 |
| Certified nurse midwife | 1 |