| Nurse practitioner | 544 |
| Physician assistant | 272 |
| Internal medicine | 155 |
| Certified Registered Nurse Anesthetist (CRNA) | 131 |
| Family practice | 130 |
| Physical therapist (private practice) | 95 |
| Hospitalist | 82 |
| Licensed clinical social worker | 72 |
| Chiropractic | 70 |
| Emergency medicine | 66 |
| Diagnostic Radiology | 64 |
| Mental Health Counselors | 57 |
| Optometrist | 48 |
| Anesthesiology | 48 |
| Centralized Flu | 47 |
| Cardiology | 39 |
| Obstetrics/gynecology | 39 |
| Podiatry | 38 |
| Mass Immunization Roster Billers | 37 |
| Clinical psychologist | 32 |
| Orthopedic surgery | 32 |
| General surgery | 31 |
| Neurology | 30 |
| Ophthalmology | 30 |
| Psychiatry | 29 |
| Dermatology | 28 |
| Gastroenterology | 27 |
| Occupational therapist (private practice) | 26 |
| Anesthesiologist Assistant | 24 |
| Pediatric medicine | 22 |
| Hematology/oncology | 21 |
| Urology | 20 |
| Pulmonary disease | 20 |
| Infectious disease | 19 |
| General practice | 15 |
| Pathology | 13 |
| Registered Dietician/Nutrition Professional | 13 |
| Vascular surgery | 13 |
| Ambulatory Surgical Center | 12 |
| Nephrology | 12 |
| Otolaryngology | 11 |
| Physical medicine and rehabilitation | 11 |
| Neurosurgery | 9 |
| Critical care (intensivists) | 9 |
| Pain Management | 9 |
| Audiologist (billing independently) | 9 |
| Interventional Cardiology | 8 |
| Rheumatology | 7 |
| Speech / language pathology | 7 |
| Pharmacy | 7 |
| Plastic and reconstructive surgery | 7 |
| Certified nurse midwife | 6 |
| Marriage and Family Therapist | 6 |
| Independent Diagnostic Testing Facility (IDTF) | 6 |
| Endocrinology | 6 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 5 |
| Allergy/immunology | 4 |
| Geriatric medicine | 4 |
| Radiation oncology | 4 |
| Clinical Laboratory (Billing Independently) | 4 |
| Thoracic surgery | 3 |
| Interventional Pain Management (IPM) | 3 |
| Hand surgery | 2 |
| Addiction medicine | 2 |
| Micrographic Dermatologic Surgery | 2 |
| Dentist | 2 |
| Colorectal surgery (formerly proctology) | 2 |
| Osteopathic manipulative therapy | 2 |
| Interventional radiology | 2 |
| Hospice and Palliative Care | 2 |
| Surgical oncology | 2 |
| Sports Medicine | 2 |
| Portable X-Ray Supplier (Billing Independently) | 1 |
| Medical Genetics and Genomics | 1 |
| Preventive medicine | 1 |
| Opioid Treatment Program | 1 |
| Hematopoietic Cell Transplantation and Cellular Therapy | 1 |
| Cardiac Electrophysiology | 1 |
| Gynecologist/oncologist | 1 |
| Sleep Medicine | 1 |
| Home Infusion Therapy Services | 1 |
| Medicare Diabetes Preventive Program | 1 |
| Single or Multispecialty Clinic or Group Practice | 1 |
| Hematology | 1 |
| Certified clinical nurse specialist | 1 |
| Cardiac surgery | 1 |