| Nurse practitioner | 2,013 |
| Physician assistant | 1,180 |
| Internal medicine | 925 |
| Physical therapist (private practice) | 764 |
| Family practice | 666 |
| Anesthesiologist Assistant | 399 |
| Emergency medicine | 379 |
| Certified Registered Nurse Anesthetist (CRNA) | 344 |
| Anesthesiology | 329 |
| Obstetrics/gynecology | 315 |
| Optometrist | 267 |
| Chiropractic | 245 |
| Diagnostic Radiology | 238 |
| Mass Immunization Roster Billers | 238 |
| Hospitalist | 223 |
| Licensed clinical social worker | 199 |
| General surgery | 197 |
| Mental Health Counselors | 182 |
| Cardiology | 175 |
| Psychiatry | 168 |
| Orthopedic surgery | 167 |
| Neurology | 159 |
| Centralized Flu | 152 |
| Gastroenterology | 140 |
| Ophthalmology | 136 |
| Dermatology | 136 |
| Occupational therapist (private practice) | 122 |
| Clinical psychologist | 116 |
| Nephrology | 103 |
| Pulmonary disease | 103 |
| Ambulatory Surgical Center | 102 |
| Otolaryngology | 101 |
| Podiatry | 98 |
| Physical medicine and rehabilitation | 95 |
| Urology | 90 |
| Pathology | 89 |
| Infectious disease | 83 |
| Hematology/oncology | 75 |
| Critical care (intensivists) | 70 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 69 |
| Endocrinology | 65 |
| Audiologist (billing independently) | 63 |
| Radiation oncology | 52 |
| Rheumatology | 47 |
| Vascular surgery | 44 |
| Neurosurgery | 42 |
| Interventional Cardiology | 40 |
| Medical oncology | 37 |
| Speech / language pathology | 34 |
| Certified nurse midwife | 32 |
| Plastic and reconstructive surgery | 31 |
| Registered Dietician/Nutrition Professional | 29 |
| Pediatric medicine | 29 |
| Pain Management | 25 |
| General practice | 24 |
| Hospice and Palliative Care | 23 |
| Colorectal surgery (formerly proctology) | 22 |
| Interventional radiology | 21 |
| Allergy/immunology | 20 |
| Thoracic surgery | 20 |
| Hand surgery | 19 |
| Hematology | 19 |
| Marriage and Family Therapist | 18 |
| Clinical Laboratory (Billing Independently) | 18 |
| Sports Medicine | 17 |
| Pharmacy | 15 |
| Cardiac Electrophysiology | 15 |
| Independent Diagnostic Testing Facility (IDTF) | 14 |
| Certified clinical nurse specialist | 13 |
| Nuclear medicine | 13 |
| Psychologist (billing independently) | 12 |
| Interventional Pain Management (IPM) | 11 |
| Surgical oncology | 11 |
| Oral surgery (dentists only) | 11 |
| Advanced Heart Failure and Transplant Cardiology | 10 |
| Maxillofacial surgery | 10 |
| Gynecologist/oncologist | 10 |
| Geriatric medicine | 9 |
| Opioid Treatment Program | 7 |
| Cardiac surgery | 7 |
| Sleep Medicine | 6 |
| Preventive medicine | 5 |
| Medical Genetics and Genomics | 4 |
| Undersea and Hyperbaric Medicine | 4 |
| Dentist | 3 |
| Micrographic Dermatologic Surgery | 3 |
| Public Health or Welfare Agencies (Federal, State, and local) | 3 |
| Hematopoietic Cell Transplantation and Cellular Therapy | 2 |
| Neuropsychiatry | 2 |
| General Psychiatry | 2 |
| Epileptologists | 2 |
| Single or Multispecialty Clinic or Group Practice | 2 |
| Unknown Provider | 1 |
| Portable X-Ray Supplier (Billing Independently) | 1 |
| Adult Congenital Heart Disease | 1 |
| Oral and Maxillofacial Pathology | 1 |
| Osteopathic manipulative therapy | 1 |
| Unknown physician specialty | 1 |
| Addiction medicine | 1 |