| Nurse practitioner | 2,789 |
| Physician assistant | 904 |
| Certified Registered Nurse Anesthetist (CRNA) | 901 |
| Internal medicine | 884 |
| Family practice | 766 |
| Physical therapist (private practice) | 709 |
| Emergency medicine | 505 |
| Obstetrics/gynecology | 321 |
| Licensed clinical social worker | 304 |
| Anesthesiology | 295 |
| Diagnostic Radiology | 255 |
| Mass Immunization Roster Billers | 251 |
| General surgery | 243 |
| Orthopedic surgery | 223 |
| Optometrist | 220 |
| Chiropractic | 196 |
| Psychiatry | 186 |
| Mental Health Counselors | 185 |
| Cardiology | 166 |
| Ophthalmology | 163 |
| Neurology | 148 |
| Occupational therapist (private practice) | 142 |
| Hospitalist | 140 |
| Dermatology | 135 |
| Gastroenterology | 132 |
| Pathology | 123 |
| Otolaryngology | 113 |
| Urology | 109 |
| Hematology/oncology | 105 |
| Nephrology | 104 |
| Pulmonary disease | 100 |
| Clinical psychologist | 100 |
| Centralized Flu | 99 |
| Pediatric medicine | 98 |
| Podiatry | 97 |
| Audiologist (billing independently) | 87 |
| Pharmacy | 84 |
| Physical medicine and rehabilitation | 68 |
| Interventional Cardiology | 66 |
| Neurosurgery | 58 |
| Ambulatory Surgical Center | 53 |
| Infectious disease | 49 |
| Rheumatology | 48 |
| Speech / language pathology | 46 |
| Radiation oncology | 42 |
| Endocrinology | 42 |
| General practice | 39 |
| Registered Dietician/Nutrition Professional | 37 |
| Allergy/immunology | 37 |
| Vascular surgery | 36 |
| Plastic and reconstructive surgery | 31 |
| Pain Management | 28 |
| Clinical Laboratory (Billing Independently) | 28 |
| Thoracic surgery | 27 |
| Critical care (intensivists) | 27 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 26 |
| Independent Diagnostic Testing Facility (IDTF) | 25 |
| Interventional Pain Management (IPM) | 25 |
| Interventional radiology | 24 |
| Cardiac Electrophysiology | 23 |
| Sports Medicine | 20 |
| Colorectal surgery (formerly proctology) | 17 |
| Hospice and Palliative Care | 15 |
| Certified nurse midwife | 15 |
| Surgical oncology | 13 |
| Gynecologist/oncologist | 12 |
| Hand surgery | 11 |
| Marriage and Family Therapist | 10 |
| Portable X-Ray Supplier (Billing Independently) | 9 |
| Oral surgery (dentists only) | 9 |
| Advanced Heart Failure and Transplant Cardiology | 8 |
| Maxillofacial surgery | 8 |
| Certified clinical nurse specialist | 7 |
| Cardiac surgery | 6 |
| Undersea and Hyperbaric Medicine | 6 |
| Dentist | 6 |
| Medical oncology | 6 |
| Geriatric medicine | 6 |
| Opioid Treatment Program | 5 |
| Preventive medicine | 4 |
| Sleep Medicine | 4 |
| Nuclear medicine | 4 |
| Addiction medicine | 4 |
| Osteopathic manipulative therapy | 4 |
| Micrographic Dermatologic Surgery | 2 |
| Epileptologists | 2 |
| Single or Multispecialty Clinic or Group Practice | 2 |
| Hematopoietic Cell Transplantation and Cellular Therapy | 2 |
| Medical Genetics and Genomics | 2 |
| Home Infusion Therapy Services | 2 |
| Hematology | 1 |