| Nurse practitioner | 514 |
| Physician assistant | 356 |
| Licensed clinical social worker | 268 |
| Internal medicine | 234 |
| Physical therapist (private practice) | 219 |
| Anesthesiology | 128 |
| Family practice | 124 |
| Emergency medicine | 104 |
| Psychiatry | 92 |
| Chiropractic | 83 |
| Obstetrics/gynecology | 79 |
| Hospitalist | 77 |
| Cardiology | 69 |
| Clinical psychologist | 68 |
| Diagnostic Radiology | 67 |
| Mass Immunization Roster Billers | 66 |
| General surgery | 62 |
| Podiatry | 53 |
| Orthopedic surgery | 52 |
| Optometrist | 51 |
| Mental Health Counselors | 51 |
| Certified Registered Nurse Anesthetist (CRNA) | 48 |
| Neurology | 47 |
| Pediatric medicine | 44 |
| Occupational therapist (private practice) | 43 |
| Gastroenterology | 43 |
| Ophthalmology | 40 |
| Pulmonary disease | 31 |
| Physical medicine and rehabilitation | 28 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 26 |
| Urology | 24 |
| Pathology | 24 |
| Otolaryngology | 23 |
| Hematology/oncology | 23 |
| Dermatology | 23 |
| Certified nurse midwife | 22 |
| Endocrinology | 19 |
| Infectious disease | 17 |
| Centralized Flu | 17 |
| Nephrology | 16 |
| Audiologist (billing independently) | 16 |
| Speech / language pathology | 14 |
| Critical care (intensivists) | 14 |
| Registered Dietician/Nutrition Professional | 14 |
| Neurosurgery | 12 |
| Rheumatology | 12 |
| Vascular surgery | 11 |
| Ambulatory Surgical Center | 11 |
| Pharmacy | 10 |
| Allergy/immunology | 9 |
| Interventional Cardiology | 9 |
| Plastic and reconstructive surgery | 9 |
| Interventional radiology | 8 |
| Radiation oncology | 8 |
| General practice | 8 |
| Hand surgery | 7 |
| Thoracic surgery | 7 |
| Pain Management | 6 |
| Cardiac Electrophysiology | 6 |
| Medical oncology | 6 |
| Gynecologist/oncologist | 5 |
| Hospice and Palliative Care | 5 |
| Sports Medicine | 5 |
| Surgical oncology | 4 |
| Oral surgery (dentists only) | 4 |
| Advanced Heart Failure and Transplant Cardiology | 3 |
| Marriage and Family Therapist | 3 |
| Opioid Treatment Program | 3 |
| Clinical Laboratory (Billing Independently) | 3 |
| Maxillofacial surgery | 3 |
| Cardiac surgery | 3 |
| Hematology | 2 |
| Sleep Medicine | 2 |
| Geriatric medicine | 2 |
| Colorectal surgery (formerly proctology) | 2 |
| Intensive Cardiac Rehabilitation | 1 |
| Micrographic Dermatologic Surgery | 1 |
| Addiction medicine | 1 |
| Certified clinical nurse specialist | 1 |
| Neuropsychiatry | 1 |
| Single or Multispecialty Clinic or Group Practice | 1 |
| Preventive medicine | 1 |
| Epileptologists | 1 |
| Medical Genetics and Genomics | 1 |