| Physician assistant | 2,026 |
| Nurse practitioner | 1,748 |
| Certified Registered Nurse Anesthetist (CRNA) | 877 |
| Internal medicine | 873 |
| Family practice | 755 |
| Physical therapist (private practice) | 629 |
| Chiropractic | 491 |
| Emergency medicine | 416 |
| Licensed clinical social worker | 407 |
| Anesthesiology | 358 |
| Diagnostic Radiology | 357 |
| Mental Health Counselors | 343 |
| Optometrist | 331 |
| Mass Immunization Roster Billers | 313 |
| Obstetrics/gynecology | 289 |
| Psychiatry | 277 |
| Clinical psychologist | 263 |
| Orthopedic surgery | 226 |
| Cardiology | 205 |
| General surgery | 187 |
| Hospitalist | 186 |
| Ophthalmology | 167 |
| Pathology | 159 |
| Neurology | 158 |
| Pulmonary disease | 141 |
| Gastroenterology | 141 |
| Podiatry | 137 |
| Occupational therapist (private practice) | 107 |
| Physical medicine and rehabilitation | 106 |
| Pediatric medicine | 104 |
| Nephrology | 92 |
| Dermatology | 91 |
| Critical care (intensivists) | 89 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 82 |
| Audiologist (billing independently) | 80 |
| Otolaryngology | 77 |
| Medical oncology | 76 |
| Infectious disease | 74 |
| Urology | 74 |
| Endocrinology | 63 |
| Speech / language pathology | 60 |
| Neurosurgery | 60 |
| Radiation oncology | 58 |
| Rheumatology | 54 |
| Thoracic surgery | 47 |
| Registered Dietician/Nutrition Professional | 44 |
| Hematology/oncology | 42 |
| Plastic and reconstructive surgery | 42 |
| Ambulatory Surgical Center | 41 |
| Vascular surgery | 33 |
| Centralized Flu | 31 |
| Interventional Cardiology | 31 |
| Hematology | 28 |
| Hospice and Palliative Care | 28 |
| Oral surgery (dentists only) | 28 |
| Pharmacy | 25 |
| Certified nurse midwife | 24 |
| Geriatric medicine | 22 |
| Sports Medicine | 22 |
| Pain Management | 21 |
| Opioid Treatment Program | 20 |
| Cardiac surgery | 18 |
| Allergy/immunology | 18 |
| Interventional radiology | 15 |
| Maxillofacial surgery | 14 |
| Colorectal surgery (formerly proctology) | 13 |
| Cardiac Electrophysiology | 12 |
| Marriage and Family Therapist | 12 |
| General practice | 11 |
| Surgical oncology | 10 |
| Clinical Laboratory (Billing Independently) | 9 |
| Dentist | 9 |
| Hand surgery | 9 |
| General Psychiatry | 8 |
| Certified clinical nurse specialist | 8 |
| Sleep Medicine | 8 |
| Gynecologist/oncologist | 8 |
| Independent Diagnostic Testing Facility (IDTF) | 8 |
| Psychologist (billing independently) | 7 |
| Micrographic Dermatologic Surgery | 5 |
| Interventional Pain Management (IPM) | 5 |
| Addiction medicine | 4 |
| Nuclear medicine | 4 |
| Advanced Heart Failure and Transplant Cardiology | 4 |
| Osteopathic manipulative therapy | 3 |
| Home Infusion Therapy Services | 1 |
| Medicare Diabetes Preventive Program | 1 |
| All other suppliers, e.g., Drug Stores | 1 |
| Portable X-Ray Supplier (Billing Independently) | 1 |
| Medical Genetics and Genomics | 1 |
| Preventive medicine | 1 |
| Single or Multispecialty Clinic or Group Practice | 1 |