| Nurse practitioner | 4,503 |
| Physician assistant | 2,428 |
| Physical therapist (private practice) | 1,735 |
| Internal medicine | 1,512 |
| Family practice | 1,494 |
| Certified Registered Nurse Anesthetist (CRNA) | 1,086 |
| Licensed clinical social worker | 1,028 |
| Emergency medicine | 929 |
| Mental Health Counselors | 899 |
| Anesthesiology | 707 |
| Optometrist | 605 |
| Obstetrics/gynecology | 564 |
| Mass Immunization Roster Billers | 520 |
| Diagnostic Radiology | 495 |
| Chiropractic | 479 |
| Psychiatry | 438 |
| Hospitalist | 426 |
| General surgery | 402 |
| Clinical psychologist | 390 |
| Orthopedic surgery | 376 |
| Ophthalmology | 294 |
| Cardiology | 293 |
| Neurology | 282 |
| Gastroenterology | 274 |
| Occupational therapist (private practice) | 272 |
| Podiatry | 246 |
| Dermatology | 227 |
| Pulmonary disease | 185 |
| Centralized Flu | 180 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 179 |
| Audiologist (billing independently) | 167 |
| Pathology | 163 |
| Urology | 163 |
| Hematology/oncology | 157 |
| Otolaryngology | 151 |
| Physical medicine and rehabilitation | 150 |
| Nephrology | 142 |
| Speech / language pathology | 114 |
| Endocrinology | 112 |
| Infectious disease | 102 |
| Interventional Cardiology | 98 |
| Certified nurse midwife | 96 |
| Critical care (intensivists) | 94 |
| Pediatric medicine | 92 |
| Registered Dietician/Nutrition Professional | 82 |
| Plastic and reconstructive surgery | 81 |
| Neurosurgery | 80 |
| Rheumatology | 80 |
| Radiation oncology | 79 |
| Allergy/immunology | 73 |
| Vascular surgery | 61 |
| Interventional radiology | 60 |
| Pharmacy | 58 |
| Marriage and Family Therapist | 56 |
| Cardiac Electrophysiology | 55 |
| Ambulatory Surgical Center | 51 |
| Medical oncology | 48 |
| Thoracic surgery | 47 |
| Sports Medicine | 42 |
| Public Health or Welfare Agencies (Federal, State, and local) | 38 |
| General practice | 37 |
| Geriatric medicine | 37 |
| Interventional Pain Management (IPM) | 34 |
| Hand surgery | 31 |
| Pain Management | 30 |
| Colorectal surgery (formerly proctology) | 29 |
| Hospice and Palliative Care | 29 |
| Clinical Laboratory (Billing Independently) | 27 |
| Opioid Treatment Program | 24 |
| Independent Diagnostic Testing Facility (IDTF) | 23 |
| Cardiac surgery | 21 |
| Sleep Medicine | 20 |
| Gynecologist/oncologist | 19 |
| Oral surgery (dentists only) | 18 |
| Surgical oncology | 18 |
| Advanced Heart Failure and Transplant Cardiology | 18 |
| Osteopathic manipulative therapy | 17 |
| Nuclear medicine | 16 |
| Addiction medicine | 16 |
| Certified clinical nurse specialist | 14 |
| Hematology | 13 |
| Dentist | 12 |
| Psychologist (billing independently) | 8 |
| Preventive medicine | 7 |
| Micrographic Dermatologic Surgery | 7 |
| Epileptologists | 5 |
| Neuropsychiatry | 5 |
| Medical Genetics and Genomics | 5 |
| General Psychiatry | 5 |
| Home Infusion Therapy Services | 4 |
| Maxillofacial surgery | 4 |
| All other suppliers, e.g., Drug Stores | 3 |
| Medicare Diabetes Preventive Program | 2 |
| Portable X-Ray Supplier (Billing Independently) | 2 |
| Medical Toxicology | 2 |
| Radiation Therapy Centers | 1 |
| Anesthesiologist Assistant | 1 |
| Adult Congenital Heart Disease | 1 |
| Hematopoietic Cell Transplantation and Cellular Therapy | 1 |
| Peripheral vascular disease | 1 |
| Orofacial Pain | 1 |
| Unknown Provider | 1 |
| Undersea and Hyperbaric Medicine | 1 |