| Nurse practitioner | 366 |
| Physician assistant | 209 |
| Internal medicine | 149 |
| Certified Registered Nurse Anesthetist (CRNA) | 149 |
| Physical therapist (private practice) | 138 |
| Family practice | 102 |
| Chiropractic | 64 |
| Hospitalist | 63 |
| Emergency medicine | 62 |
| Diagnostic Radiology | 57 |
| Licensed clinical social worker | 54 |
| Mental Health Counselors | 46 |
| Anesthesiology | 45 |
| Orthopedic surgery | 41 |
| Cardiology | 38 |
| Ophthalmology | 38 |
| Centralized Flu | 38 |
| Optometrist | 37 |
| Dermatology | 36 |
| Neurology | 32 |
| Obstetrics/gynecology | 32 |
| Clinical psychologist | 31 |
| Podiatry | 30 |
| Mass Immunization Roster Billers | 29 |
| Occupational therapist (private practice) | 28 |
| Gastroenterology | 27 |
| Psychiatry | 27 |
| Urology | 19 |
| General surgery | 19 |
| Ambulatory Surgical Center | 19 |
| Critical care (intensivists) | 18 |
| Speech / language pathology | 17 |
| Pathology | 17 |
| Pulmonary disease | 15 |
| Otolaryngology | 14 |
| Interventional Cardiology | 13 |
| Physical medicine and rehabilitation | 12 |
| Neurosurgery | 12 |
| General practice | 10 |
| Nephrology | 10 |
| Vascular surgery | 9 |
| Hematology/oncology | 8 |
| Medical oncology | 8 |
| Pediatric medicine | 7 |
| Plastic and reconstructive surgery | 7 |
| Marriage and Family Therapist | 7 |
| Interventional Pain Management (IPM) | 7 |
| Infectious disease | 7 |
| Interventional radiology | 7 |
| Thoracic surgery | 7 |
| Radiation oncology | 7 |
| Cardiac Electrophysiology | 6 |
| Pain Management | 6 |
| Audiologist (billing independently) | 6 |
| Registered Dietician/Nutrition Professional | 5 |
| Certified nurse midwife | 5 |
| Allergy/immunology | 5 |
| Clinical Laboratory (Billing Independently) | 5 |
| Endocrinology | 4 |
| Rheumatology | 4 |
| Pharmacy | 3 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 3 |
| Nuclear medicine | 3 |
| Gynecologist/oncologist | 3 |
| Micrographic Dermatologic Surgery | 3 |
| Surgical oncology | 3 |
| Colorectal surgery (formerly proctology) | 3 |
| Hospice and Palliative Care | 3 |
| Sports Medicine | 3 |
| Preventive medicine | 2 |
| Geriatric medicine | 2 |
| Oral surgery (dentists only) | 2 |
| Epileptologists | 2 |
| Single or Multispecialty Clinic or Group Practice | 1 |
| Home Infusion Therapy Services | 1 |
| Advanced Heart Failure and Transplant Cardiology | 1 |
| Medical Genetics and Genomics | 1 |
| Hand surgery | 1 |
| Opioid Treatment Program | 1 |