| Nurse practitioner | 392 |
| Internal medicine | 150 |
| Family practice | 144 |
| Physical therapist (private practice) | 125 |
| Physician assistant | 113 |
| Certified Registered Nurse Anesthetist (CRNA) | 111 |
| Mental Health Counselors | 106 |
| Licensed clinical social worker | 99 |
| Chiropractic | 63 |
| Mass Immunization Roster Billers | 47 |
| Emergency medicine | 42 |
| Diagnostic Radiology | 42 |
| General surgery | 41 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 39 |
| Optometrist | 38 |
| Orthopedic surgery | 36 |
| Podiatry | 35 |
| Obstetrics/gynecology | 28 |
| Anesthesiology | 28 |
| Clinical psychologist | 28 |
| Certified clinical nurse specialist | 24 |
| Pediatric medicine | 21 |
| Cardiology | 20 |
| Audiologist (billing independently) | 20 |
| Occupational therapist (private practice) | 17 |
| Ophthalmology | 16 |
| Psychiatry | 14 |
| Hospitalist | 13 |
| Physical medicine and rehabilitation | 13 |
| Pathology | 13 |
| Dermatology | 12 |
| Pulmonary disease | 12 |
| Centralized Flu | 12 |
| Gastroenterology | 11 |
| Urology | 10 |
| Critical care (intensivists) | 10 |
| Ambulatory Surgical Center | 10 |
| Infectious disease | 9 |
| Nephrology | 9 |
| Otolaryngology | 9 |
| Plastic and reconstructive surgery | 7 |
| Hematology/oncology | 7 |
| Neurology | 7 |
| Certified nurse midwife | 7 |
| Pain Management | 7 |
| Registered Dietician/Nutrition Professional | 6 |
| Interventional Cardiology | 6 |
| Allergy/immunology | 5 |
| Independent Diagnostic Testing Facility (IDTF) | 5 |
| Radiation oncology | 5 |
| Thoracic surgery | 5 |
| Anesthesiologist Assistant | 5 |
| Endocrinology | 5 |
| Speech / language pathology | 4 |
| Opioid Treatment Program | 4 |
| Vascular surgery | 4 |
| Clinical Laboratory (Billing Independently) | 3 |
| Maxillofacial surgery | 3 |
| Cardiac Electrophysiology | 3 |
| Rheumatology | 3 |
| Single or Multispecialty Clinic or Group Practice | 3 |
| Interventional radiology | 2 |
| Sports Medicine | 2 |
| Hand surgery | 2 |
| Colorectal surgery (formerly proctology) | 2 |
| Neurosurgery | 2 |
| General practice | 2 |
| Interventional Pain Management (IPM) | 2 |
| Pharmacy | 1 |
| Medical oncology | 1 |
| Public Health or Welfare Agencies (Federal, State, and local) | 1 |
| Marriage and Family Therapist | 1 |
| Sleep Medicine | 1 |
| Geriatric medicine | 1 |
| Hospice and Palliative Care | 1 |
| Portable X-Ray Supplier (Billing Independently) | 1 |