| Nurse practitioner | 1,588 |
| Physician assistant | 1,535 |
| Family practice | 911 |
| Internal medicine | 894 |
| Physical therapist (private practice) | 849 |
| Licensed clinical social worker | 731 |
| Certified Registered Nurse Anesthetist (CRNA) | 680 |
| Chiropractic | 572 |
| Mental Health Counselors | 541 |
| Clinical psychologist | 483 |
| Emergency medicine | 434 |
| Marriage and Family Therapist | 369 |
| Optometrist | 305 |
| Obstetrics/gynecology | 296 |
| Diagnostic Radiology | 259 |
| Anesthesiology | 255 |
| Psychiatry | 228 |
| Occupational therapist (private practice) | 203 |
| Orthopedic surgery | 188 |
| Cardiology | 155 |
| Ophthalmology | 146 |
| Neurology | 143 |
| General surgery | 142 |
| Mass Immunization Roster Billers | 137 |
| Pathology | 118 |
| Dermatology | 113 |
| Pediatric medicine | 107 |
| Gastroenterology | 102 |
| Audiologist (billing independently) | 94 |
| Registered Dietician/Nutrition Professional | 91 |
| Certified nurse midwife | 83 |
| Podiatry | 83 |
| Physical medicine and rehabilitation | 80 |
| Speech / language pathology | 78 |
| Centralized Flu | 76 |
| Nephrology | 73 |
| Otolaryngology | 73 |
| Pulmonary disease | 70 |
| Hematology/oncology | 68 |
| Urology | 64 |
| Infectious disease | 56 |
| Certified clinical nurse specialist | 45 |
| Neurosurgery | 41 |
| Endocrinology | 41 |
| Sports Medicine | 39 |
| Hospitalist | 39 |
| Critical care (intensivists) | 38 |
| Ambulatory Surgical Center | 36 |
| Rheumatology | 35 |
| Medical oncology | 30 |
| Radiation oncology | 29 |
| Vascular surgery | 27 |
| Allergy/immunology | 24 |
| Cardiac Electrophysiology | 23 |
| Colorectal surgery (formerly proctology) | 23 |
| Plastic and reconstructive surgery | 21 |
| Interventional Cardiology | 21 |
| Oral surgery (dentists only) | 21 |
| Maxillofacial surgery | 17 |
| Interventional radiology | 17 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 16 |
| Hospice and Palliative Care | 15 |
| Hand surgery | 14 |
| Pain Management | 14 |
| Geriatric medicine | 13 |
| Thoracic surgery | 13 |
| Gynecologist/oncologist | 10 |
| Cardiac surgery | 9 |
| Preventive medicine | 9 |
| Clinical Laboratory (Billing Independently) | 8 |
| Pharmacy | 8 |
| Opioid Treatment Program | 7 |
| Dentist | 7 |
| Micrographic Dermatologic Surgery | 6 |
| Addiction medicine | 6 |
| Interventional Pain Management (IPM) | 6 |
| Sleep Medicine | 5 |
| Neuropsychiatry | 4 |
| General practice | 4 |
| Advanced Heart Failure and Transplant Cardiology | 4 |
| Epileptologists | 3 |
| Independent Diagnostic Testing Facility (IDTF) | 2 |
| Hematology | 2 |
| Portable X-Ray Supplier (Billing Independently) | 2 |
| Surgical oncology | 2 |
| Undersea and Hyperbaric Medicine | 2 |
| Home Infusion Therapy Services | 2 |
| Medical Genetics and Genomics | 2 |
| Unknown physician specialty | 1 |
| Single or Multispecialty Clinic or Group Practice | 1 |
| Peripheral vascular disease | 1 |
| Osteopathic manipulative therapy | 1 |
| Psychologist (billing independently) | 1 |
| Prosthodontics | 1 |