| Nurse practitioner | 1,996 |
| Physician assistant | 1,006 |
| Internal medicine | 912 |
| Physical therapist (private practice) | 847 |
| Licensed clinical social worker | 555 |
| Anesthesiology | 363 |
| Emergency medicine | 348 |
| Family practice | 324 |
| Certified Registered Nurse Anesthetist (CRNA) | 313 |
| Mental Health Counselors | 279 |
| Obstetrics/gynecology | 258 |
| Psychiatry | 239 |
| Diagnostic Radiology | 237 |
| Hospitalist | 210 |
| Orthopedic surgery | 174 |
| Cardiology | 166 |
| Neurology | 166 |
| Clinical psychologist | 164 |
| Optometrist | 163 |
| General surgery | 159 |
| Ophthalmology | 150 |
| Occupational therapist (private practice) | 136 |
| Chiropractic | 131 |
| Mass Immunization Roster Billers | 130 |
| Gastroenterology | 112 |
| Pathology | 101 |
| Pediatric medicine | 99 |
| Critical care (intensivists) | 98 |
| Dermatology | 96 |
| Podiatry | 90 |
| Nephrology | 88 |
| Ambulatory Surgical Center | 88 |
| Infectious disease | 85 |
| Pulmonary disease | 81 |
| Urology | 79 |
| Physical medicine and rehabilitation | 79 |
| Audiologist (billing independently) | 79 |
| Endocrinology | 78 |
| Centralized Flu | 75 |
| Otolaryngology | 67 |
| Hematology/oncology | 56 |
| Medical oncology | 55 |
| Speech / language pathology | 54 |
| Rheumatology | 49 |
| Certified nurse midwife | 48 |
| Radiation oncology | 43 |
| Plastic and reconstructive surgery | 39 |
| Neurosurgery | 39 |
| Vascular surgery | 37 |
| Registered Dietician/Nutrition Professional | 37 |
| Opioid Treatment Program | 35 |
| Geriatric medicine | 30 |
| General practice | 20 |
| Thoracic surgery | 19 |
| Pharmacy | 18 |
| Allergy/immunology | 18 |
| Interventional radiology | 17 |
| Clinical Laboratory (Billing Independently) | 17 |
| Interventional Pain Management (IPM) | 16 |
| Hospice and Palliative Care | 16 |
| Pain Management | 16 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 14 |
| Cardiac surgery | 14 |
| Interventional Cardiology | 13 |
| Cardiac Electrophysiology | 13 |
| Hand surgery | 12 |
| Colorectal surgery (formerly proctology) | 11 |
| Marriage and Family Therapist | 10 |
| Sports Medicine | 9 |
| Advanced Heart Failure and Transplant Cardiology | 9 |
| Maxillofacial surgery | 8 |
| Hematology | 8 |
| Sleep Medicine | 8 |
| Certified clinical nurse specialist | 8 |
| Independent Diagnostic Testing Facility (IDTF) | 8 |
| Surgical oncology | 7 |
| Neuropsychiatry | 7 |
| Gynecologist/oncologist | 6 |
| Micrographic Dermatologic Surgery | 6 |
| Nuclear medicine | 5 |
| Oral surgery (dentists only) | 4 |
| Medical Genetics and Genomics | 4 |
| Dentist | 4 |
| Preventive medicine | 3 |
| Osteopathic manipulative therapy | 2 |
| Single or Multispecialty Clinic or Group Practice | 2 |
| Medicare Diabetes Preventive Program | 2 |
| General Psychiatry | 2 |
| Home Infusion Therapy Services | 1 |
| Addiction medicine | 1 |
| Portable X-Ray Supplier (Billing Independently) | 1 |
| Psychologist (billing independently) | 1 |