| Physician assistant | 1,623 |
| Nurse practitioner | 1,471 |
| Physical therapist (private practice) | 1,159 |
| Licensed clinical social worker | 835 |
| Internal medicine | 753 |
| Anesthesiology | 538 |
| Family practice | 468 |
| Diagnostic Radiology | 458 |
| Clinical psychologist | 362 |
| Emergency medicine | 352 |
| Psychiatry | 324 |
| Obstetrics/gynecology | 297 |
| Cardiology | 294 |
| Certified Registered Nurse Anesthetist (CRNA) | 288 |
| Occupational therapist (private practice) | 288 |
| Chiropractic | 279 |
| Hospitalist | 279 |
| Podiatry | 220 |
| Gastroenterology | 197 |
| Orthopedic surgery | 193 |
| Neurology | 182 |
| Pathology | 181 |
| Ophthalmology | 179 |
| General surgery | 179 |
| Optometrist | 155 |
| Mental Health Counselors | 151 |
| Dermatology | 150 |
| Mass Immunization Roster Billers | 141 |
| Hematology/oncology | 112 |
| Pulmonary disease | 106 |
| Endocrinology | 103 |
| Physical medicine and rehabilitation | 103 |
| Audiologist (billing independently) | 96 |
| Urology | 90 |
| Pediatric medicine | 88 |
| Nephrology | 81 |
| Speech / language pathology | 77 |
| Otolaryngology | 77 |
| Plastic and reconstructive surgery | 76 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 71 |
| Registered Dietician/Nutrition Professional | 70 |
| Infectious disease | 62 |
| Interventional Cardiology | 58 |
| Rheumatology | 58 |
| Allergy/immunology | 56 |
| Neurosurgery | 55 |
| Centralized Flu | 55 |
| Critical care (intensivists) | 54 |
| Medical oncology | 52 |
| Vascular surgery | 43 |
| Pain Management | 41 |
| Interventional radiology | 40 |
| Radiation oncology | 40 |
| Thoracic surgery | 28 |
| Colorectal surgery (formerly proctology) | 28 |
| Hospice and Palliative Care | 25 |
| Cardiac Electrophysiology | 24 |
| Certified nurse midwife | 23 |
| Pharmacy | 23 |
| Nuclear medicine | 23 |
| Geriatric medicine | 23 |
| Clinical Laboratory (Billing Independently) | 23 |
| Ambulatory Surgical Center | 21 |
| Oral surgery (dentists only) | 20 |
| Surgical oncology | 16 |
| Interventional Pain Management (IPM) | 16 |
| Cardiac surgery | 15 |
| Gynecologist/oncologist | 14 |
| General practice | 14 |
| Osteopathic manipulative therapy | 13 |
| Independent Diagnostic Testing Facility (IDTF) | 13 |
| Hand surgery | 12 |
| Sports Medicine | 11 |
| Maxillofacial surgery | 9 |
| Advanced Heart Failure and Transplant Cardiology | 9 |
| Hematology | 8 |
| Marriage and Family Therapist | 7 |
| Certified clinical nurse specialist | 6 |
| Addiction medicine | 5 |
| General Psychiatry | 4 |
| Medical Genetics and Genomics | 4 |
| Opioid Treatment Program | 3 |
| Dentist | 3 |
| Sleep Medicine | 3 |
| Micrographic Dermatologic Surgery | 3 |
| Medical Toxicology | 3 |
| Portable X-Ray Supplier (Billing Independently) | 3 |
| Unknown physician specialty | 3 |
| Preventive medicine | 3 |
| Epileptologists | 2 |
| Undersea and Hyperbaric Medicine | 2 |
| Adult Congenital Heart Disease | 2 |
| Single or Multispecialty Clinic or Group Practice | 2 |
| Unknown Provider | 1 |
| Hematopoietic Cell Transplantation and Cellular Therapy | 1 |
| Neuropsychiatry | 1 |
| Radiation Therapy Centers | 1 |