| Nurse practitioner | 6,691 |
| Physical therapist (private practice) | 4,695 |
| Internal medicine | 3,803 |
| Physician assistant | 3,289 |
| Licensed clinical social worker | 2,329 |
| Family practice | 1,922 |
| Anesthesiology | 1,626 |
| Chiropractic | 1,594 |
| Emergency medicine | 1,383 |
| Occupational therapist (private practice) | 1,221 |
| Obstetrics/gynecology | 1,197 |
| Certified Registered Nurse Anesthetist (CRNA) | 1,048 |
| Diagnostic Radiology | 1,002 |
| Optometrist | 966 |
| Cardiology | 959 |
| Podiatry | 956 |
| Clinical psychologist | 946 |
| Psychiatry | 902 |
| Mass Immunization Roster Billers | 843 |
| Mental Health Counselors | 768 |
| Orthopedic surgery | 699 |
| Gastroenterology | 616 |
| General surgery | 607 |
| Ophthalmology | 597 |
| Neurology | 584 |
| Physical medicine and rehabilitation | 470 |
| Pulmonary disease | 388 |
| Dermatology | 386 |
| Hospitalist | 349 |
| Hematology/oncology | 340 |
| Urology | 334 |
| Nephrology | 328 |
| Endocrinology | 315 |
| Pediatric medicine | 313 |
| Speech / language pathology | 309 |
| Otolaryngology | 306 |
| Pathology | 304 |
| Infectious disease | 269 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 269 |
| Centralized Flu | 264 |
| Ambulatory Surgical Center | 220 |
| Registered Dietician/Nutrition Professional | 213 |
| Rheumatology | 208 |
| Audiologist (billing independently) | 207 |
| Plastic and reconstructive surgery | 183 |
| Critical care (intensivists) | 173 |
| Neurosurgery | 163 |
| Vascular surgery | 155 |
| Allergy/immunology | 143 |
| Certified nurse midwife | 142 |
| Pharmacy | 140 |
| Radiation oncology | 139 |
| Pain Management | 132 |
| Interventional Cardiology | 123 |
| Medical oncology | 118 |
| Marriage and Family Therapist | 118 |
| Interventional radiology | 100 |
| Thoracic surgery | 95 |
| Cardiac Electrophysiology | 79 |
| Geriatric medicine | 78 |
| Colorectal surgery (formerly proctology) | 77 |
| Sports Medicine | 73 |
| Clinical Laboratory (Billing Independently) | 72 |
| Oral surgery (dentists only) | 65 |
| Surgical oncology | 64 |
| General practice | 62 |
| Hand surgery | 61 |
| Independent Diagnostic Testing Facility (IDTF) | 55 |
| Interventional Pain Management (IPM) | 48 |
| Certified clinical nurse specialist | 45 |
| Gynecologist/oncologist | 39 |
| Opioid Treatment Program | 36 |
| Hospice and Palliative Care | 33 |
| Cardiac surgery | 33 |
| Addiction medicine | 26 |
| Nuclear medicine | 25 |
| Osteopathic manipulative therapy | 22 |
| Hematology | 21 |
| Advanced Heart Failure and Transplant Cardiology | 20 |
| Sleep Medicine | 20 |
| Maxillofacial surgery | 20 |
| Dentist | 16 |
| General Psychiatry | 12 |
| Micrographic Dermatologic Surgery | 11 |
| Single or Multispecialty Clinic or Group Practice | 11 |
| Preventive medicine | 10 |
| Psychologist (billing independently) | 10 |
| Home Infusion Therapy Services | 7 |
| Portable X-Ray Supplier (Billing Independently) | 6 |
| Epileptologists | 5 |
| Neuropsychiatry | 3 |
| Medicare Diabetes Preventive Program | 3 |
| Hematopoietic Cell Transplantation and Cellular Therapy | 2 |
| Medical Genetics and Genomics | 2 |
| Public Health or Welfare Agencies (Federal, State, and local) | 1 |
| Unknown Provider | 1 |
| Oral Medicine | 1 |
| All other suppliers, e.g., Drug Stores | 1 |