| Nurse practitioner | 1,294 |
| Physical therapist (private practice) | 724 |
| Physician assistant | 713 |
| Internal medicine | 588 |
| Family practice | 490 |
| Certified Registered Nurse Anesthetist (CRNA) | 320 |
| Licensed clinical social worker | 311 |
| Emergency medicine | 270 |
| Anesthesiology | 250 |
| Optometrist | 226 |
| Mental Health Counselors | 220 |
| Obstetrics/gynecology | 192 |
| Psychiatry | 177 |
| Chiropractic | 170 |
| Hospitalist | 159 |
| Diagnostic Radiology | 155 |
| Orthopedic surgery | 149 |
| Mass Immunization Roster Billers | 139 |
| Ophthalmology | 120 |
| General surgery | 118 |
| Occupational therapist (private practice) | 115 |
| Cardiology | 115 |
| Clinical psychologist | 114 |
| Podiatry | 105 |
| Dermatology | 98 |
| Gastroenterology | 97 |
| Neurology | 95 |
| Centralized Flu | 77 |
| Pathology | 56 |
| Audiologist (billing independently) | 54 |
| Urology | 49 |
| Otolaryngology | 48 |
| Hematology/oncology | 45 |
| Critical care (intensivists) | 44 |
| Pulmonary disease | 43 |
| Physical medicine and rehabilitation | 42 |
| Nephrology | 39 |
| Speech / language pathology | 39 |
| Endocrinology | 37 |
| Allergy/immunology | 34 |
| Certified nurse midwife | 34 |
| Pediatric medicine | 32 |
| Infectious disease | 28 |
| Interventional radiology | 25 |
| Registered Dietician/Nutrition Professional | 25 |
| Rheumatology | 24 |
| Interventional Cardiology | 24 |
| Plastic and reconstructive surgery | 24 |
| Medical oncology | 23 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 23 |
| Radiation oncology | 21 |
| Neurosurgery | 18 |
| Interventional Pain Management (IPM) | 18 |
| Ambulatory Surgical Center | 18 |
| General practice | 17 |
| Vascular surgery | 15 |
| Pharmacy | 14 |
| Marriage and Family Therapist | 14 |
| Cardiac Electrophysiology | 14 |
| Colorectal surgery (formerly proctology) | 12 |
| Thoracic surgery | 11 |
| Sports Medicine | 11 |
| Pain Management | 10 |
| Independent Diagnostic Testing Facility (IDTF) | 9 |
| Geriatric medicine | 9 |
| Hematology | 7 |
| Gynecologist/oncologist | 7 |
| Advanced Heart Failure and Transplant Cardiology | 7 |
| Nuclear medicine | 6 |
| Clinical Laboratory (Billing Independently) | 6 |
| Surgical oncology | 6 |
| Hospice and Palliative Care | 5 |
| Oral surgery (dentists only) | 5 |
| Sleep Medicine | 5 |
| Certified clinical nurse specialist | 4 |
| Osteopathic manipulative therapy | 4 |
| Hand surgery | 4 |
| Medical Genetics and Genomics | 4 |
| Addiction medicine | 4 |
| Public Health or Welfare Agencies (Federal, State, and local) | 4 |
| Cardiac surgery | 3 |
| Preventive medicine | 3 |
| Opioid Treatment Program | 3 |
| Micrographic Dermatologic Surgery | 3 |
| Psychologist (billing independently) | 2 |
| General Psychiatry | 2 |
| Radiation Therapy Centers | 1 |
| Anesthesiologist Assistant | 1 |
| Adult Congenital Heart Disease | 1 |
| Orofacial Pain | 1 |
| Dentist | 1 |
| Home Infusion Therapy Services | 1 |
| Neuropsychiatry | 1 |
| Epileptologists | 1 |
| All other suppliers, e.g., Drug Stores | 1 |
| Medicare Diabetes Preventive Program | 1 |
| Undersea and Hyperbaric Medicine | 1 |