| Nurse practitioner | 1,036 |
| Physical therapist (private practice) | 683 |
| Physician assistant | 583 |
| Family practice | 459 |
| Internal medicine | 372 |
| Licensed clinical social worker | 288 |
| Certified Registered Nurse Anesthetist (CRNA) | 288 |
| Mental Health Counselors | 244 |
| Clinical psychologist | 239 |
| Chiropractic | 216 |
| Optometrist | 171 |
| Anesthesiology | 168 |
| Obstetrics/gynecology | 163 |
| Diagnostic Radiology | 157 |
| Psychiatry | 151 |
| Emergency medicine | 150 |
| Mass Immunization Roster Billers | 128 |
| Occupational therapist (private practice) | 116 |
| Cardiology | 112 |
| Podiatry | 105 |
| Ophthalmology | 95 |
| General surgery | 94 |
| Dermatology | 89 |
| Orthopedic surgery | 89 |
| Neurology | 81 |
| Gastroenterology | 77 |
| Hospitalist | 74 |
| Audiologist (billing independently) | 65 |
| Hematology/oncology | 63 |
| Physical medicine and rehabilitation | 61 |
| Otolaryngology | 61 |
| Urology | 56 |
| Pathology | 56 |
| Speech / language pathology | 52 |
| Registered Dietician/Nutrition Professional | 49 |
| Pulmonary disease | 46 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 44 |
| Centralized Flu | 41 |
| Rheumatology | 39 |
| Endocrinology | 32 |
| Ambulatory Surgical Center | 31 |
| Nephrology | 30 |
| Radiation oncology | 30 |
| Neurosurgery | 28 |
| Infectious disease | 26 |
| Plastic and reconstructive surgery | 25 |
| Pharmacy | 23 |
| Interventional Cardiology | 22 |
| Marriage and Family Therapist | 21 |
| Cardiac Electrophysiology | 21 |
| Allergy/immunology | 20 |
| Pain Management | 18 |
| Vascular surgery | 18 |
| Medical oncology | 18 |
| Oral surgery (dentists only) | 16 |
| Thoracic surgery | 14 |
| Critical care (intensivists) | 14 |
| Pediatric medicine | 13 |
| Maxillofacial surgery | 12 |
| Sports Medicine | 12 |
| Hand surgery | 11 |
| Certified nurse midwife | 10 |
| Micrographic Dermatologic Surgery | 10 |
| General practice | 9 |
| Independent Diagnostic Testing Facility (IDTF) | 9 |
| Interventional radiology | 8 |
| Colorectal surgery (formerly proctology) | 8 |
| Cardiac surgery | 7 |
| Certified clinical nurse specialist | 7 |
| Geriatric medicine | 6 |
| Osteopathic manipulative therapy | 6 |
| Opioid Treatment Program | 6 |
| Hematology | 6 |
| Gynecologist/oncologist | 6 |
| Hematopoietic Cell Transplantation and Cellular Therapy | 5 |
| Surgical oncology | 5 |
| Advanced Heart Failure and Transplant Cardiology | 5 |
| Clinical Laboratory (Billing Independently) | 5 |
| Hospice and Palliative Care | 5 |
| Nuclear medicine | 3 |
| Medicare Diabetes Preventive Program | 3 |
| General Psychiatry | 2 |
| Dentist | 2 |
| Interventional Pain Management (IPM) | 2 |
| Neuropsychiatry | 1 |
| Psychologist (billing independently) | 1 |
| Sleep Medicine | 1 |
| Addiction medicine | 1 |
| Undersea and Hyperbaric Medicine | 1 |
| Medical Genetics and Genomics | 1 |