| Physical therapist (private practice) | 853 |
| Nurse practitioner | 784 |
| Internal medicine | 728 |
| Family practice | 690 |
| Physician assistant | 663 |
| Emergency medicine | 402 |
| Anesthesiology | 334 |
| Clinical psychologist | 327 |
| Diagnostic Radiology | 224 |
| Psychiatry | 216 |
| Chiropractic | 198 |
| Optometrist | 198 |
| Licensed clinical social worker | 193 |
| Hospitalist | 190 |
| Marriage and Family Therapist | 189 |
| Obstetrics/gynecology | 186 |
| Ophthalmology | 141 |
| Dermatology | 138 |
| Orthopedic surgery | 138 |
| Mass Immunization Roster Billers | 134 |
| Cardiology | 126 |
| General surgery | 125 |
| Occupational therapist (private practice) | 121 |
| Neurology | 109 |
| Gastroenterology | 104 |
| Certified Registered Nurse Anesthetist (CRNA) | 95 |
| Pathology | 88 |
| Podiatry | 85 |
| Urology | 78 |
| Hematology/oncology | 78 |
| Otolaryngology | 75 |
| Critical care (intensivists) | 66 |
| Nephrology | 65 |
| Pulmonary disease | 62 |
| Physical medicine and rehabilitation | 59 |
| Speech / language pathology | 52 |
| Geriatric medicine | 45 |
| Endocrinology | 45 |
| Interventional radiology | 42 |
| Audiologist (billing independently) | 40 |
| Radiation oncology | 39 |
| Infectious disease | 39 |
| General practice | 37 |
| Rheumatology | 37 |
| Plastic and reconstructive surgery | 35 |
| Neurosurgery | 33 |
| Ambulatory Surgical Center | 31 |
| Registered Dietician/Nutrition Professional | 31 |
| Mental Health Counselors | 29 |
| Allergy/immunology | 28 |
| Interventional Cardiology | 25 |
| Centralized Flu | 25 |
| Vascular surgery | 24 |
| Pediatric medicine | 24 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 23 |
| Pain Management | 22 |
| Clinical Laboratory (Billing Independently) | 21 |
| Psychologist (billing independently) | 17 |
| Cardiac Electrophysiology | 17 |
| Hospice and Palliative Care | 16 |
| Hand surgery | 16 |
| Preventive medicine | 15 |
| Medical oncology | 14 |
| Thoracic surgery | 14 |
| Certified nurse midwife | 14 |
| Sports Medicine | 13 |
| Osteopathic manipulative therapy | 12 |
| Advanced Heart Failure and Transplant Cardiology | 12 |
| Colorectal surgery (formerly proctology) | 10 |
| Pharmacy | 8 |
| Nuclear medicine | 8 |
| Cardiac surgery | 7 |
| Interventional Pain Management (IPM) | 7 |
| Neuropsychiatry | 6 |
| Unknown physician specialty | 6 |
| Sleep Medicine | 6 |
| Oral surgery (dentists only) | 6 |
| Gynecologist/oncologist | 6 |
| Micrographic Dermatologic Surgery | 6 |
| Dentist | 5 |
| Independent Diagnostic Testing Facility (IDTF) | 5 |
| Opioid Treatment Program | 5 |
| Surgical oncology | 4 |
| Hematology | 4 |
| Maxillofacial surgery | 3 |
| Portable X-Ray Supplier (Billing Independently) | 3 |
| Unknown Provider | 2 |
| Undersea and Hyperbaric Medicine | 2 |
| Addiction medicine | 2 |
| Medical Genetics and Genomics | 2 |
| General Psychiatry | 1 |
| Single or Multispecialty Clinic or Group Practice | 1 |
| Adult Congenital Heart Disease | 1 |