| Nurse practitioner | 618 |
| Physician assistant | 523 |
| Physical therapist (private practice) | 441 |
| Family practice | 326 |
| Licensed clinical social worker | 301 |
| Mental Health Counselors | 178 |
| Chiropractic | 175 |
| Internal medicine | 160 |
| Anesthesiology | 157 |
| Emergency medicine | 136 |
| Optometrist | 113 |
| Certified Registered Nurse Anesthetist (CRNA) | 97 |
| Orthopedic surgery | 80 |
| Obstetrics/gynecology | 74 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 71 |
| General surgery | 65 |
| Mass Immunization Roster Billers | 59 |
| Diagnostic Radiology | 59 |
| Psychiatry | 56 |
| Occupational therapist (private practice) | 54 |
| Hospitalist | 51 |
| Clinical psychologist | 51 |
| Cardiology | 36 |
| Neurology | 32 |
| Podiatry | 32 |
| Dermatology | 30 |
| Ophthalmology | 30 |
| Audiologist (billing independently) | 29 |
| Urology | 28 |
| Pulmonary disease | 27 |
| Speech / language pathology | 26 |
| Gastroenterology | 25 |
| Otolaryngology | 24 |
| Hematology/oncology | 24 |
| Pathology | 22 |
| Neurosurgery | 18 |
| Physical medicine and rehabilitation | 17 |
| Ambulatory Surgical Center | 16 |
| Nephrology | 15 |
| Interventional Cardiology | 14 |
| Rheumatology | 13 |
| Infectious disease | 12 |
| Critical care (intensivists) | 12 |
| Registered Dietician/Nutrition Professional | 12 |
| Radiation oncology | 11 |
| Pediatric medicine | 11 |
| Thoracic surgery | 11 |
| General practice | 11 |
| Centralized Flu | 11 |
| Pharmacy | 10 |
| Plastic and reconstructive surgery | 10 |
| Certified nurse midwife | 10 |
| Endocrinology | 9 |
| Medical oncology | 9 |
| Gynecologist/oncologist | 8 |
| Interventional radiology | 8 |
| Vascular surgery | 7 |
| Allergy/immunology | 7 |
| Public Health or Welfare Agencies (Federal, State, and local) | 6 |
| Cardiac Electrophysiology | 6 |
| Sleep Medicine | 6 |
| Osteopathic manipulative therapy | 6 |
| Hand surgery | 6 |
| Preventive medicine | 5 |
| Certified clinical nurse specialist | 5 |
| Independent Diagnostic Testing Facility (IDTF) | 5 |
| Marriage and Family Therapist | 5 |
| Hospice and Palliative Care | 5 |
| Clinical Laboratory (Billing Independently) | 5 |
| Unknown Provider | 4 |
| Pain Management | 4 |
| Geriatric medicine | 4 |
| Opioid Treatment Program | 3 |
| Oral surgery (dentists only) | 3 |
| Psychologist (billing independently) | 3 |
| Interventional Pain Management (IPM) | 3 |
| Colorectal surgery (formerly proctology) | 2 |
| Sports Medicine | 2 |
| Surgical oncology | 2 |
| Portable X-Ray Supplier (Billing Independently) | 2 |
| Cardiac surgery | 1 |
| Hematology | 1 |
| Medicare Diabetes Preventive Program | 1 |
| Advanced Heart Failure and Transplant Cardiology | 1 |
| Micrographic Dermatologic Surgery | 1 |