| Nurse practitioner | 3,217 |
| Physician assistant | 1,723 |
| Internal medicine | 1,547 |
| Family practice | 1,227 |
| Physical therapist (private practice) | 1,068 |
| Anesthesiology | 877 |
| Emergency medicine | 688 |
| Certified Registered Nurse Anesthetist (CRNA) | 684 |
| Optometrist | 531 |
| Diagnostic Radiology | 530 |
| Chiropractic | 467 |
| Obstetrics/gynecology | 452 |
| Mental Health Counselors | 395 |
| Mass Immunization Roster Billers | 393 |
| Psychiatry | 336 |
| Orthopedic surgery | 327 |
| Licensed clinical social worker | 325 |
| General surgery | 290 |
| Cardiology | 288 |
| Clinical psychologist | 285 |
| Gastroenterology | 261 |
| Neurology | 238 |
| Ophthalmology | 230 |
| Dermatology | 212 |
| Nephrology | 211 |
| Pediatric medicine | 207 |
| Pathology | 205 |
| Podiatry | 199 |
| Physical medicine and rehabilitation | 166 |
| Hospitalist | 163 |
| Occupational therapist (private practice) | 163 |
| Pulmonary disease | 150 |
| Otolaryngology | 136 |
| Audiologist (billing independently) | 124 |
| Centralized Flu | 123 |
| Hematology/oncology | 120 |
| Registered Dietician/Nutrition Professional | 117 |
| Infectious disease | 113 |
| Endocrinology | 108 |
| Urology | 106 |
| Interventional Cardiology | 93 |
| Ambulatory Surgical Center | 90 |
| Medical oncology | 87 |
| Speech / language pathology | 79 |
| Plastic and reconstructive surgery | 78 |
| Rheumatology | 78 |
| Independent Diagnostic Testing Facility (IDTF) | 77 |
| Neurosurgery | 76 |
| Allergy/immunology | 70 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 64 |
| Radiation oncology | 58 |
| Pharmacy | 58 |
| Vascular surgery | 57 |
| Thoracic surgery | 55 |
| Critical care (intensivists) | 50 |
| Colorectal surgery (formerly proctology) | 50 |
| Pain Management | 46 |
| Clinical Laboratory (Billing Independently) | 43 |
| Cardiac Electrophysiology | 38 |
| General practice | 38 |
| Surgical oncology | 35 |
| Interventional radiology | 35 |
| Geriatric medicine | 34 |
| Hospice and Palliative Care | 32 |
| Interventional Pain Management (IPM) | 31 |
| Marriage and Family Therapist | 28 |
| Certified nurse midwife | 20 |
| Hand surgery | 19 |
| Oral surgery (dentists only) | 17 |
| Anesthesiologist Assistant | 15 |
| Advanced Heart Failure and Transplant Cardiology | 14 |
| Certified clinical nurse specialist | 12 |
| Sports Medicine | 11 |
| Gynecologist/oncologist | 11 |
| Opioid Treatment Program | 9 |
| Micrographic Dermatologic Surgery | 9 |
| Osteopathic manipulative therapy | 8 |
| Nuclear medicine | 7 |
| Portable X-Ray Supplier (Billing Independently) | 7 |
| Maxillofacial surgery | 7 |
| Sleep Medicine | 7 |
| Hematopoietic Cell Transplantation and Cellular Therapy | 5 |
| Cardiac surgery | 5 |
| Dentist | 5 |
| Oral and Maxillofacial Pathology | 4 |
| Hematology | 4 |
| Preventive medicine | 4 |
| Psychologist (billing independently) | 3 |
| Single or Multispecialty Clinic or Group Practice | 3 |
| General Psychiatry | 2 |
| Home Infusion Therapy Services | 1 |
| Addiction medicine | 1 |
| Medical Genetics and Genomics | 1 |