| Nurse practitioner | 3,365 |
| Physician assistant | 2,022 |
| Family practice | 1,445 |
| Physical therapist (private practice) | 1,181 |
| Chiropractic | 1,043 |
| Internal medicine | 808 |
| Mental Health Counselors | 805 |
| Licensed clinical social worker | 731 |
| Emergency medicine | 694 |
| Certified Registered Nurse Anesthetist (CRNA) | 638 |
| Anesthesiology | 586 |
| Optometrist | 496 |
| Diagnostic Radiology | 485 |
| Hospitalist | 420 |
| Obstetrics/gynecology | 382 |
| Clinical psychologist | 378 |
| Mass Immunization Roster Billers | 359 |
| General surgery | 339 |
| Orthopedic surgery | 327 |
| Psychiatry | 323 |
| Occupational therapist (private practice) | 257 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 212 |
| Cardiology | 209 |
| Ophthalmology | 183 |
| Neurology | 180 |
| Gastroenterology | 170 |
| Podiatry | 169 |
| Centralized Flu | 157 |
| Pathology | 152 |
| Dermatology | 149 |
| Hematology/oncology | 148 |
| Pulmonary disease | 133 |
| Audiologist (billing independently) | 130 |
| Anesthesiologist Assistant | 125 |
| Urology | 123 |
| Physical medicine and rehabilitation | 119 |
| Pediatric medicine | 113 |
| Otolaryngology | 112 |
| Marriage and Family Therapist | 112 |
| Nephrology | 109 |
| Registered Dietician/Nutrition Professional | 107 |
| Endocrinology | 105 |
| Radiation oncology | 85 |
| Infectious disease | 83 |
| Critical care (intensivists) | 76 |
| Speech / language pathology | 75 |
| Neurosurgery | 75 |
| Pharmacy | 64 |
| Certified nurse midwife | 61 |
| Rheumatology | 59 |
| Ambulatory Surgical Center | 56 |
| Interventional Cardiology | 56 |
| Allergy/immunology | 50 |
| Plastic and reconstructive surgery | 49 |
| Cardiac Electrophysiology | 39 |
| Interventional radiology | 37 |
| Pain Management | 37 |
| Vascular surgery | 36 |
| Medical oncology | 34 |
| Geriatric medicine | 28 |
| Sports Medicine | 28 |
| Hospice and Palliative Care | 27 |
| Surgical oncology | 25 |
| Oral surgery (dentists only) | 20 |
| Hand surgery | 20 |
| General practice | 20 |
| Thoracic surgery | 20 |
| Sleep Medicine | 18 |
| Interventional Pain Management (IPM) | 15 |
| Colorectal surgery (formerly proctology) | 15 |
| Cardiac surgery | 14 |
| Preventive medicine | 13 |
| Clinical Laboratory (Billing Independently) | 13 |
| Undersea and Hyperbaric Medicine | 12 |
| Independent Diagnostic Testing Facility (IDTF) | 12 |
| Gynecologist/oncologist | 11 |
| Maxillofacial surgery | 11 |
| Opioid Treatment Program | 10 |
| Certified clinical nurse specialist | 10 |
| Nuclear medicine | 8 |
| Addiction medicine | 7 |
| Advanced Heart Failure and Transplant Cardiology | 7 |
| Micrographic Dermatologic Surgery | 7 |
| Single or Multispecialty Clinic or Group Practice | 7 |
| Osteopathic manipulative therapy | 6 |
| Medical Genetics and Genomics | 5 |
| Hematology | 5 |
| Neuropsychiatry | 4 |
| Hematopoietic Cell Transplantation and Cellular Therapy | 4 |
| Medicare Diabetes Preventive Program | 3 |
| Epileptologists | 3 |
| Portable X-Ray Supplier (Billing Independently) | 2 |
| General Psychiatry | 2 |
| Home Infusion Therapy Services | 1 |
| Dentist | 1 |
| All other suppliers, e.g., Drug Stores | 1 |
| Adult Congenital Heart Disease | 1 |