| Nurse practitioner | 1,392 |
| Internal medicine | 655 |
| Physical therapist (private practice) | 562 |
| Physician assistant | 556 |
| Licensed clinical social worker | 401 |
| Certified Registered Nurse Anesthetist (CRNA) | 362 |
| Family practice | 305 |
| Anesthesiology | 231 |
| Chiropractic | 227 |
| Emergency medicine | 212 |
| Diagnostic Radiology | 199 |
| Obstetrics/gynecology | 190 |
| Clinical psychologist | 176 |
| Dermatology | 164 |
| Mental Health Counselors | 155 |
| Podiatry | 147 |
| Orthopedic surgery | 146 |
| Ophthalmology | 144 |
| Cardiology | 141 |
| Optometrist | 138 |
| Centralized Flu | 135 |
| Occupational therapist (private practice) | 123 |
| Psychiatry | 119 |
| Neurology | 104 |
| Gastroenterology | 96 |
| Mass Immunization Roster Billers | 89 |
| General surgery | 81 |
| Anesthesiologist Assistant | 78 |
| Otolaryngology | 69 |
| Pathology | 62 |
| Urology | 59 |
| Speech / language pathology | 55 |
| Audiologist (billing independently) | 55 |
| Hematology/oncology | 53 |
| General practice | 48 |
| Ambulatory Surgical Center | 47 |
| Physical medicine and rehabilitation | 47 |
| Nephrology | 44 |
| Plastic and reconstructive surgery | 44 |
| Rheumatology | 42 |
| Pulmonary disease | 42 |
| Endocrinology | 39 |
| Infectious disease | 39 |
| Neurosurgery | 36 |
| Radiation oncology | 33 |
| Clinical Laboratory (Billing Independently) | 32 |
| Registered Dietician/Nutrition Professional | 31 |
| Critical care (intensivists) | 31 |
| Interventional Pain Management (IPM) | 28 |
| Pain Management | 24 |
| Hospitalist | 22 |
| Thoracic surgery | 22 |
| Independent Diagnostic Testing Facility (IDTF) | 21 |
| Medical oncology | 21 |
| Marriage and Family Therapist | 21 |
| Interventional Cardiology | 21 |
| Allergy/immunology | 19 |
| Vascular surgery | 18 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 17 |
| Certified nurse midwife | 17 |
| Oral surgery (dentists only) | 16 |
| Cardiac Electrophysiology | 16 |
| Pediatric medicine | 15 |
| Colorectal surgery (formerly proctology) | 14 |
| Interventional radiology | 13 |
| Hand surgery | 12 |
| Pharmacy | 10 |
| Sports Medicine | 10 |
| Psychologist (billing independently) | 8 |
| Surgical oncology | 8 |
| Osteopathic manipulative therapy | 7 |
| Cardiac surgery | 6 |
| Gynecologist/oncologist | 6 |
| Hospice and Palliative Care | 5 |
| Geriatric medicine | 5 |
| Preventive medicine | 4 |
| Nuclear medicine | 4 |
| Micrographic Dermatologic Surgery | 3 |
| Hematology | 3 |
| Sleep Medicine | 2 |
| Opioid Treatment Program | 2 |
| Maxillofacial surgery | 2 |
| General Psychiatry | 2 |
| Medical Genetics and Genomics | 1 |
| Dentist | 1 |
| Portable X-Ray Supplier (Billing Independently) | 1 |
| Epileptologists | 1 |
| Advanced Heart Failure and Transplant Cardiology | 1 |
| Oral and Maxillofacial Pathology | 1 |
| Home Infusion Therapy Services | 1 |