| Nurse practitioner | 631 |
| Internal medicine | 359 |
| Physician assistant | 336 |
| Physical therapist (private practice) | 322 |
| Licensed clinical social worker | 277 |
| Family practice | 165 |
| Emergency medicine | 136 |
| Clinical psychologist | 126 |
| Mental Health Counselors | 123 |
| Optometrist | 120 |
| Psychiatry | 108 |
| Obstetrics/gynecology | 85 |
| Certified Registered Nurse Anesthetist (CRNA) | 82 |
| Anesthesiology | 74 |
| Chiropractic | 70 |
| Diagnostic Radiology | 60 |
| Orthopedic surgery | 59 |
| Mass Immunization Roster Billers | 54 |
| Cardiology | 53 |
| Neurology | 48 |
| General surgery | 45 |
| Ophthalmology | 43 |
| Gastroenterology | 43 |
| Occupational therapist (private practice) | 42 |
| Pathology | 39 |
| Podiatry | 36 |
| Registered Dietician/Nutrition Professional | 35 |
| Pulmonary disease | 33 |
| Centralized Flu | 32 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 31 |
| Dermatology | 31 |
| Hematology/oncology | 29 |
| Urology | 27 |
| Certified nurse midwife | 23 |
| Infectious disease | 21 |
| Audiologist (billing independently) | 21 |
| Nephrology | 19 |
| Pediatric medicine | 19 |
| Otolaryngology | 16 |
| Opioid Treatment Program | 15 |
| Endocrinology | 13 |
| Plastic and reconstructive surgery | 13 |
| Certified clinical nurse specialist | 13 |
| Ambulatory Surgical Center | 12 |
| Geriatric medicine | 12 |
| Speech / language pathology | 12 |
| Physical medicine and rehabilitation | 12 |
| Radiation oncology | 11 |
| Interventional Cardiology | 9 |
| Neurosurgery | 9 |
| Pharmacy | 9 |
| Rheumatology | 9 |
| Hospice and Palliative Care | 9 |
| Hospitalist | 7 |
| Thoracic surgery | 7 |
| Hand surgery | 7 |
| Surgical oncology | 6 |
| Interventional radiology | 6 |
| Vascular surgery | 5 |
| Marriage and Family Therapist | 5 |
| Medical oncology | 4 |
| Allergy/immunology | 4 |
| Cardiac Electrophysiology | 4 |
| General practice | 3 |
| Colorectal surgery (formerly proctology) | 3 |
| Osteopathic manipulative therapy | 3 |
| Gynecologist/oncologist | 3 |
| Addiction medicine | 3 |
| Critical care (intensivists) | 3 |
| Independent Diagnostic Testing Facility (IDTF) | 3 |
| Pain Management | 2 |
| Advanced Heart Failure and Transplant Cardiology | 2 |
| Clinical Laboratory (Billing Independently) | 2 |
| Neuropsychiatry | 2 |
| Sports Medicine | 2 |
| Portable X-Ray Supplier (Billing Independently) | 2 |
| Maxillofacial surgery | 2 |
| Preventive medicine | 1 |
| Medicare Diabetes Preventive Program | 1 |
| Unknown physician specialty | 1 |
| Sleep Medicine | 1 |
| Single or Multispecialty Clinic or Group Practice | 1 |
| Cardiac surgery | 1 |
| Oral surgery (dentists only) | 1 |