| Nurse practitioner | 1,737 |
| Physician assistant | 1,514 |
| Family practice | 1,036 |
| Physical therapist (private practice) | 1,034 |
| Internal medicine | 862 |
| Licensed clinical social worker | 653 |
| Emergency medicine | 538 |
| Anesthesiology | 434 |
| Mental Health Counselors | 415 |
| Chiropractic | 411 |
| Optometrist | 350 |
| Certified Registered Nurse Anesthetist (CRNA) | 341 |
| Clinical psychologist | 305 |
| Obstetrics/gynecology | 294 |
| Diagnostic Radiology | 249 |
| Psychiatry | 234 |
| Hospitalist | 231 |
| General surgery | 220 |
| Orthopedic surgery | 195 |
| Ophthalmology | 175 |
| Mass Immunization Roster Billers | 150 |
| Neurology | 142 |
| Cardiology | 126 |
| Gastroenterology | 122 |
| Dermatology | 121 |
| Podiatry | 112 |
| Occupational therapist (private practice) | 108 |
| Pathology | 97 |
| Otolaryngology | 97 |
| Pediatric medicine | 91 |
| Pulmonary disease | 90 |
| Certified nurse midwife | 83 |
| Urology | 81 |
| Registered Dietician/Nutrition Professional | 76 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 74 |
| Marriage and Family Therapist | 72 |
| Audiologist (billing independently) | 68 |
| Hematology/oncology | 68 |
| Nephrology | 63 |
| Neurosurgery | 55 |
| Radiation oncology | 53 |
| Ambulatory Surgical Center | 52 |
| Medical oncology | 51 |
| Physical medicine and rehabilitation | 48 |
| Endocrinology | 47 |
| Infectious disease | 45 |
| Rheumatology | 45 |
| Centralized Flu | 45 |
| Speech / language pathology | 43 |
| Interventional Cardiology | 36 |
| Vascular surgery | 31 |
| Plastic and reconstructive surgery | 31 |
| Critical care (intensivists) | 30 |
| Clinical Laboratory (Billing Independently) | 26 |
| Interventional radiology | 24 |
| Hospice and Palliative Care | 22 |
| Cardiac Electrophysiology | 22 |
| Allergy/immunology | 22 |
| Thoracic surgery | 19 |
| Pain Management | 19 |
| General practice | 18 |
| Sports Medicine | 17 |
| Gynecologist/oncologist | 17 |
| Pharmacy | 16 |
| Hand surgery | 15 |
| Unknown Provider | 13 |
| Interventional Pain Management (IPM) | 12 |
| Geriatric medicine | 12 |
| Surgical oncology | 12 |
| Sleep Medicine | 12 |
| Independent Diagnostic Testing Facility (IDTF) | 11 |
| Osteopathic manipulative therapy | 10 |
| Colorectal surgery (formerly proctology) | 10 |
| Opioid Treatment Program | 10 |
| Unknown physician specialty | 9 |
| Oral surgery (dentists only) | 7 |
| Maxillofacial surgery | 6 |
| Psychologist (billing independently) | 6 |
| Preventive medicine | 5 |
| Certified clinical nurse specialist | 5 |
| Micrographic Dermatologic Surgery | 5 |
| Cardiac surgery | 5 |
| Medicare Diabetes Preventive Program | 4 |
| Medical Genetics and Genomics | 4 |
| Hematology | 4 |
| Advanced Heart Failure and Transplant Cardiology | 4 |
| Home Infusion Therapy Services | 3 |
| Dentist | 3 |
| Addiction medicine | 2 |
| Nuclear medicine | 2 |
| Radiation Therapy Centers | 1 |
| Public Health or Welfare Agencies (Federal, State, and local) | 1 |
| Slide Preparation Facilities | 1 |
| Portable X-Ray Supplier (Billing Independently) | 1 |
| Orofacial Pain | 1 |
| Adult Congenital Heart Disease | 1 |
| Undersea and Hyperbaric Medicine | 1 |