| Nurse practitioner | 625 |
| Physician assistant | 239 |
| Physical therapist (private practice) | 230 |
| Chiropractic | 220 |
| Family practice | 194 |
| Certified Registered Nurse Anesthetist (CRNA) | 184 |
| Licensed clinical social worker | 148 |
| Mental Health Counselors | 123 |
| Optometrist | 114 |
| Hospitalist | 80 |
| Emergency medicine | 69 |
| Internal medicine | 66 |
| Clinical psychologist | 62 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 59 |
| Mass Immunization Roster Billers | 58 |
| Obstetrics/gynecology | 57 |
| Psychiatry | 53 |
| General surgery | 52 |
| Anesthesiology | 51 |
| Occupational therapist (private practice) | 47 |
| Diagnostic Radiology | 43 |
| Orthopedic surgery | 33 |
| Speech / language pathology | 31 |
| Neurology | 25 |
| Ophthalmology | 24 |
| Cardiology | 22 |
| Audiologist (billing independently) | 21 |
| Gastroenterology | 21 |
| Podiatry | 20 |
| Pathology | 20 |
| Pediatric medicine | 19 |
| Radiation oncology | 17 |
| Hematology/oncology | 17 |
| Registered Dietician/Nutrition Professional | 17 |
| Otolaryngology | 16 |
| Urology | 16 |
| Pharmacy | 15 |
| Nephrology | 14 |
| Dermatology | 14 |
| Critical care (intensivists) | 14 |
| Public Health or Welfare Agencies (Federal, State, and local) | 13 |
| Interventional Cardiology | 13 |
| Plastic and reconstructive surgery | 12 |
| Pulmonary disease | 11 |
| Neurosurgery | 11 |
| Ambulatory Surgical Center | 10 |
| General practice | 10 |
| Physical medicine and rehabilitation | 9 |
| Certified clinical nurse specialist | 8 |
| Interventional radiology | 7 |
| Sports Medicine | 7 |
| Oral surgery (dentists only) | 7 |
| Cardiac surgery | 7 |
| Cardiac Electrophysiology | 7 |
| Infectious disease | 7 |
| Rheumatology | 6 |
| Hand surgery | 5 |
| Unknown physician specialty | 5 |
| Certified nurse midwife | 5 |
| Endocrinology | 5 |
| Marriage and Family Therapist | 4 |
| Clinical Laboratory (Billing Independently) | 4 |
| Allergy/immunology | 4 |
| Vascular surgery | 4 |
| Pain Management | 4 |
| Thoracic surgery | 3 |
| Colorectal surgery (formerly proctology) | 3 |
| Opioid Treatment Program | 3 |
| Unknown Provider | 2 |
| Surgical oncology | 2 |
| Medical oncology | 2 |
| Maxillofacial surgery | 2 |
| Independent Diagnostic Testing Facility (IDTF) | 2 |
| Undersea and Hyperbaric Medicine | 1 |
| Gynecologist/oncologist | 1 |
| Geriatric medicine | 1 |
| Sleep Medicine | 1 |
| Hematology | 1 |
| Advanced Heart Failure and Transplant Cardiology | 1 |
| Medicare Diabetes Preventive Program | 1 |
| Medical Genetics and Genomics | 1 |
| Preventive medicine | 1 |
| Portable X-Ray Supplier (Billing Independently) | 1 |