| Nurse practitioner | 690 |
| Physical therapist (private practice) | 254 |
| Internal medicine | 240 |
| Family practice | 201 |
| Physician assistant | 193 |
| Anesthesiology | 166 |
| Emergency medicine | 137 |
| Diagnostic Radiology | 96 |
| Certified Registered Nurse Anesthetist (CRNA) | 95 |
| Licensed clinical social worker | 81 |
| Optometrist | 63 |
| Psychiatry | 61 |
| Mass Immunization Roster Billers | 56 |
| Mental Health Counselors | 54 |
| General surgery | 51 |
| Obstetrics/gynecology | 50 |
| Clinical psychologist | 48 |
| Orthopedic surgery | 46 |
| Chiropractic | 46 |
| Cardiology | 42 |
| Ophthalmology | 40 |
| Neurology | 39 |
| Hospitalist | 37 |
| Dermatology | 31 |
| Pathology | 31 |
| Nephrology | 29 |
| Occupational therapist (private practice) | 26 |
| Pulmonary disease | 25 |
| Gastroenterology | 24 |
| Podiatry | 23 |
| Hematology/oncology | 23 |
| Urology | 23 |
| Centralized Flu | 23 |
| Audiologist (billing independently) | 23 |
| Ambulatory Surgical Center | 20 |
| Otolaryngology | 20 |
| Pediatric medicine | 18 |
| Rheumatology | 17 |
| Interventional Cardiology | 16 |
| Neurosurgery | 15 |
| Endocrinology | 15 |
| Infectious disease | 13 |
| Registered Dietician/Nutrition Professional | 13 |
| Certified nurse midwife | 13 |
| Physical medicine and rehabilitation | 12 |
| Radiation oncology | 12 |
| Vascular surgery | 11 |
| Allergy/immunology | 9 |
| Pain Management | 8 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 8 |
| Surgical oncology | 7 |
| Critical care (intensivists) | 7 |
| Thoracic surgery | 7 |
| Speech / language pathology | 7 |
| Medical oncology | 6 |
| Clinical Laboratory (Billing Independently) | 6 |
| Plastic and reconstructive surgery | 6 |
| Geriatric medicine | 6 |
| Pharmacy | 6 |
| Cardiac Electrophysiology | 5 |
| Gynecologist/oncologist | 5 |
| Colorectal surgery (formerly proctology) | 5 |
| Marriage and Family Therapist | 4 |
| Sports Medicine | 4 |
| Opioid Treatment Program | 4 |
| General practice | 4 |
| Hospice and Palliative Care | 3 |
| Micrographic Dermatologic Surgery | 3 |
| Hand surgery | 3 |
| Sleep Medicine | 3 |
| Maxillofacial surgery | 3 |
| Cardiac surgery | 3 |
| Independent Diagnostic Testing Facility (IDTF) | 3 |
| Dentist | 2 |
| Preventive medicine | 2 |
| Osteopathic manipulative therapy | 2 |
| Unknown physician specialty | 2 |
| Nuclear medicine | 2 |
| Interventional radiology | 1 |
| Portable X-Ray Supplier (Billing Independently) | 1 |
| Single or Multispecialty Clinic or Group Practice | 1 |
| Medical Genetics and Genomics | 1 |
| Oral surgery (dentists only) | 1 |
| Medicare Diabetes Preventive Program | 1 |