| Nurse practitioner | 1,089 |
| Internal medicine | 347 |
| Physician assistant | 335 |
| Family practice | 286 |
| Certified Registered Nurse Anesthetist (CRNA) | 263 |
| Physical therapist (private practice) | 216 |
| Licensed clinical social worker | 191 |
| Emergency medicine | 160 |
| Anesthesiology | 156 |
| Obstetrics/gynecology | 149 |
| Optometrist | 129 |
| Diagnostic Radiology | 119 |
| Mental Health Counselors | 118 |
| Mass Immunization Roster Billers | 103 |
| Psychiatry | 99 |
| Clinical psychologist | 95 |
| Hospitalist | 92 |
| Chiropractic | 89 |
| Pediatric medicine | 79 |
| Orthopedic surgery | 74 |
| Cardiology | 74 |
| Neurology | 71 |
| Gastroenterology | 64 |
| General surgery | 64 |
| Ophthalmology | 57 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 56 |
| Hematology/oncology | 54 |
| Pulmonary disease | 53 |
| Podiatry | 50 |
| Nephrology | 46 |
| Audiologist (billing independently) | 42 |
| Occupational therapist (private practice) | 39 |
| Anesthesiologist Assistant | 39 |
| Dermatology | 39 |
| Pathology | 38 |
| Speech / language pathology | 34 |
| Physical medicine and rehabilitation | 31 |
| Endocrinology | 30 |
| Otolaryngology | 30 |
| Centralized Flu | 29 |
| Critical care (intensivists) | 28 |
| Infectious disease | 27 |
| Neurosurgery | 25 |
| Urology | 23 |
| Radiation oncology | 19 |
| Ambulatory Surgical Center | 19 |
| Registered Dietician/Nutrition Professional | 18 |
| Rheumatology | 18 |
| Interventional Cardiology | 17 |
| Cardiac Electrophysiology | 17 |
| Thoracic surgery | 16 |
| Certified nurse midwife | 15 |
| Vascular surgery | 14 |
| Allergy/immunology | 13 |
| Certified clinical nurse specialist | 12 |
| Plastic and reconstructive surgery | 12 |
| General practice | 11 |
| Gynecologist/oncologist | 11 |
| Advanced Heart Failure and Transplant Cardiology | 9 |
| Pain Management | 9 |
| Hand surgery | 9 |
| Pharmacy | 8 |
| Medical oncology | 8 |
| Sleep Medicine | 8 |
| Interventional radiology | 8 |
| Opioid Treatment Program | 7 |
| Sports Medicine | 7 |
| Geriatric medicine | 6 |
| Independent Diagnostic Testing Facility (IDTF) | 6 |
| Surgical oncology | 6 |
| Hematology | 5 |
| Clinical Laboratory (Billing Independently) | 5 |
| Cardiac surgery | 4 |
| Single or Multispecialty Clinic or Group Practice | 4 |
| Hospice and Palliative Care | 4 |
| Interventional Pain Management (IPM) | 3 |
| Colorectal surgery (formerly proctology) | 3 |
| Maxillofacial surgery | 3 |
| Epileptologists | 3 |
| Addiction medicine | 3 |
| Micrographic Dermatologic Surgery | 3 |
| Preventive medicine | 2 |
| Marriage and Family Therapist | 2 |
| Public Health or Welfare Agencies (Federal, State, and local) | 1 |
| Oral surgery (dentists only) | 1 |
| Hematopoietic Cell Transplantation and Cellular Therapy | 1 |
| Nuclear medicine | 1 |
| General Psychiatry | 1 |
| Home Infusion Therapy Services | 1 |