| Nurse practitioner | 3,549 |
| Family practice | 1,103 |
| Internal medicine | 1,019 |
| Physician assistant | 979 |
| Certified Registered Nurse Anesthetist (CRNA) | 943 |
| Physical therapist (private practice) | 835 |
| Chiropractic | 680 |
| Emergency medicine | 606 |
| Licensed clinical social worker | 532 |
| Optometrist | 482 |
| Mental Health Counselors | 470 |
| Anesthesiology | 453 |
| Mass Immunization Roster Billers | 449 |
| Hospitalist | 410 |
| Diagnostic Radiology | 393 |
| Obstetrics/gynecology | 390 |
| Psychiatry | 353 |
| Orthopedic surgery | 305 |
| General surgery | 294 |
| Clinical psychologist | 241 |
| Cardiology | 209 |
| Neurology | 201 |
| Gastroenterology | 198 |
| Ophthalmology | 188 |
| Occupational therapist (private practice) | 172 |
| Pathology | 164 |
| Podiatry | 147 |
| Dermatology | 147 |
| Pulmonary disease | 141 |
| Anesthesiologist Assistant | 133 |
| Centralized Flu | 129 |
| Nephrology | 129 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 126 |
| Otolaryngology | 121 |
| Critical care (intensivists) | 112 |
| Urology | 107 |
| Pediatric medicine | 107 |
| Hematology/oncology | 106 |
| Physical medicine and rehabilitation | 102 |
| Audiologist (billing independently) | 102 |
| Endocrinology | 93 |
| Neurosurgery | 87 |
| Infectious disease | 87 |
| Speech / language pathology | 79 |
| Interventional Cardiology | 69 |
| Medical oncology | 64 |
| Rheumatology | 62 |
| Radiation oncology | 61 |
| Pharmacy | 60 |
| Ambulatory Surgical Center | 58 |
| Vascular surgery | 52 |
| Plastic and reconstructive surgery | 50 |
| Allergy/immunology | 48 |
| Cardiac Electrophysiology | 41 |
| General practice | 39 |
| Pain Management | 38 |
| Sports Medicine | 36 |
| Interventional radiology | 36 |
| Registered Dietician/Nutrition Professional | 34 |
| Thoracic surgery | 33 |
| Certified clinical nurse specialist | 31 |
| Certified nurse midwife | 29 |
| Clinical Laboratory (Billing Independently) | 27 |
| Gynecologist/oncologist | 23 |
| Hospice and Palliative Care | 21 |
| Interventional Pain Management (IPM) | 21 |
| Geriatric medicine | 20 |
| Cardiac surgery | 19 |
| Hand surgery | 17 |
| Marriage and Family Therapist | 17 |
| Sleep Medicine | 17 |
| Independent Diagnostic Testing Facility (IDTF) | 16 |
| Colorectal surgery (formerly proctology) | 15 |
| Advanced Heart Failure and Transplant Cardiology | 15 |
| Maxillofacial surgery | 13 |
| Osteopathic manipulative therapy | 12 |
| Nuclear medicine | 11 |
| Surgical oncology | 11 |
| Opioid Treatment Program | 10 |
| Epileptologists | 7 |
| Hematology | 7 |
| Micrographic Dermatologic Surgery | 6 |
| Oral surgery (dentists only) | 5 |
| Preventive medicine | 4 |
| Neuropsychiatry | 3 |
| Portable X-Ray Supplier (Billing Independently) | 3 |
| Dentist | 2 |
| Addiction medicine | 2 |
| Undersea and Hyperbaric Medicine | 2 |
| Medical Genetics and Genomics | 2 |
| General Psychiatry | 2 |
| Mammography Screening Center | 1 |
| Single or Multispecialty Clinic or Group Practice | 1 |
| Medicare Diabetes Preventive Program | 1 |
| Unknown Provider | 1 |
| Psychologist (billing independently) | 1 |
| Public Health or Welfare Agencies (Federal, State, and local) | 1 |
| Adult Congenital Heart Disease | 1 |
| All other suppliers, e.g., Drug Stores | 1 |
| Home Infusion Therapy Services | 1 |