| Nurse practitioner | 736 |
| Physician assistant | 700 |
| Internal medicine | 541 |
| Family practice | 487 |
| Physical therapist (private practice) | 464 |
| Emergency medicine | 276 |
| Licensed clinical social worker | 235 |
| Anesthesiology | 214 |
| Certified Registered Nurse Anesthetist (CRNA) | 196 |
| Clinical psychologist | 182 |
| Optometrist | 174 |
| Chiropractic | 171 |
| Obstetrics/gynecology | 162 |
| Mental Health Counselors | 155 |
| Diagnostic Radiology | 136 |
| Psychiatry | 125 |
| Hospitalist | 122 |
| Neurology | 100 |
| Ophthalmology | 91 |
| General surgery | 88 |
| Orthopedic surgery | 83 |
| Gastroenterology | 79 |
| Dermatology | 68 |
| Mass Immunization Roster Billers | 68 |
| Cardiology | 67 |
| Pathology | 62 |
| Pulmonary disease | 59 |
| Otolaryngology | 54 |
| Occupational therapist (private practice) | 51 |
| Podiatry | 51 |
| Pediatric medicine | 49 |
| Certified nurse midwife | 47 |
| Registered Dietician/Nutrition Professional | 36 |
| Nephrology | 36 |
| Urology | 36 |
| Medical oncology | 33 |
| Radiation oncology | 32 |
| Hematology/oncology | 31 |
| Endocrinology | 31 |
| Audiologist (billing independently) | 29 |
| Infectious disease | 27 |
| Neurosurgery | 26 |
| Centralized Flu | 24 |
| Marriage and Family Therapist | 22 |
| Physical medicine and rehabilitation | 21 |
| Rheumatology | 20 |
| Ambulatory Surgical Center | 19 |
| Speech / language pathology | 17 |
| Interventional radiology | 16 |
| Vascular surgery | 14 |
| Interventional Cardiology | 14 |
| Hospice and Palliative Care | 13 |
| Critical care (intensivists) | 13 |
| Plastic and reconstructive surgery | 12 |
| Thoracic surgery | 12 |
| Cardiac Electrophysiology | 12 |
| Allergy/immunology | 10 |
| Hand surgery | 9 |
| Geriatric medicine | 9 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 9 |
| Pain Management | 8 |
| Independent Diagnostic Testing Facility (IDTF) | 8 |
| Colorectal surgery (formerly proctology) | 8 |
| Sleep Medicine | 8 |
| Sports Medicine | 7 |
| Pharmacy | 7 |
| Gynecologist/oncologist | 7 |
| Clinical Laboratory (Billing Independently) | 6 |
| Surgical oncology | 6 |
| Unknown physician specialty | 5 |
| Medicare Diabetes Preventive Program | 4 |
| Interventional Pain Management (IPM) | 4 |
| General practice | 4 |
| Advanced Heart Failure and Transplant Cardiology | 4 |
| Opioid Treatment Program | 4 |
| Micrographic Dermatologic Surgery | 4 |
| Maxillofacial surgery | 3 |
| Hematology | 3 |
| Certified clinical nurse specialist | 3 |
| Home Infusion Therapy Services | 2 |
| Addiction medicine | 2 |
| Psychologist (billing independently) | 2 |
| Oral surgery (dentists only) | 2 |
| Preventive medicine | 2 |
| Osteopathic manipulative therapy | 2 |
| Radiation Therapy Centers | 1 |
| Cardiac surgery | 1 |
| Medical Genetics and Genomics | 1 |
| Portable X-Ray Supplier (Billing Independently) | 1 |
| Orofacial Pain | 1 |
| Adult Congenital Heart Disease | 1 |
| Dentist | 1 |