| Nurse practitioner | 382 |
| Physician assistant | 375 |
| Family practice | 227 |
| Licensed clinical social worker | 127 |
| Chiropractic | 119 |
| Diagnostic Radiology | 119 |
| Mental Health Counselors | 117 |
| Internal medicine | 115 |
| Physical therapist (private practice) | 109 |
| Hospitalist | 106 |
| Anesthesiology | 93 |
| Emergency medicine | 86 |
| Clinical psychologist | 84 |
| Certified Registered Nurse Anesthetist (CRNA) | 84 |
| Optometrist | 67 |
| Psychiatry | 59 |
| General surgery | 56 |
| Obstetrics/gynecology | 50 |
| Cardiology | 47 |
| Mass Immunization Roster Billers | 46 |
| Neurology | 43 |
| Orthopedic surgery | 40 |
| Anesthesiologist Assistant | 39 |
| Marriage and Family Therapist | 39 |
| Pulmonary disease | 36 |
| Gastroenterology | 36 |
| Pathology | 35 |
| Ophthalmology | 30 |
| Occupational therapist (private practice) | 28 |
| Infectious disease | 27 |
| Dermatology | 27 |
| Nephrology | 23 |
| Urology | 22 |
| Pediatric medicine | 22 |
| Endocrinology | 21 |
| Centralized Flu | 20 |
| Rheumatology | 20 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 20 |
| Audiologist (billing independently) | 19 |
| Registered Dietician/Nutrition Professional | 19 |
| Otolaryngology | 18 |
| Hematology/oncology | 17 |
| Podiatry | 16 |
| Radiation oncology | 15 |
| Neurosurgery | 15 |
| Allergy/immunology | 14 |
| Medical oncology | 13 |
| Geriatric medicine | 12 |
| Certified nurse midwife | 11 |
| Speech / language pathology | 10 |
| Cardiac Electrophysiology | 10 |
| Physical medicine and rehabilitation | 9 |
| Plastic and reconstructive surgery | 9 |
| Surgical oncology | 8 |
| Interventional radiology | 8 |
| Pharmacy | 8 |
| Sleep Medicine | 8 |
| Sports Medicine | 8 |
| Vascular surgery | 8 |
| Interventional Cardiology | 8 |
| Critical care (intensivists) | 7 |
| Pain Management | 6 |
| Hospice and Palliative Care | 6 |
| Thoracic surgery | 6 |
| Nuclear medicine | 5 |
| Cardiac surgery | 4 |
| Colorectal surgery (formerly proctology) | 4 |
| Maxillofacial surgery | 4 |
| Ambulatory Surgical Center | 4 |
| Gynecologist/oncologist | 4 |
| Hematopoietic Cell Transplantation and Cellular Therapy | 4 |
| Micrographic Dermatologic Surgery | 3 |
| Hematology | 3 |
| Advanced Heart Failure and Transplant Cardiology | 3 |
| Hand surgery | 2 |
| Interventional Pain Management (IPM) | 2 |
| Certified clinical nurse specialist | 2 |
| General practice | 2 |
| Neuropsychiatry | 2 |
| Single or Multispecialty Clinic or Group Practice | 2 |
| Independent Diagnostic Testing Facility (IDTF) | 2 |
| Preventive medicine | 1 |
| Opioid Treatment Program | 1 |
| Clinical Laboratory (Billing Independently) | 1 |
| Adult Congenital Heart Disease | 1 |
| Addiction medicine | 1 |
| Oral surgery (dentists only) | 1 |