| Nurse practitioner | 1,255 |
| Internal medicine | 783 |
| Physician assistant | 546 |
| Family practice | 422 |
| Physical therapist (private practice) | 363 |
| Certified Registered Nurse Anesthetist (CRNA) | 277 |
| Anesthesiology | 275 |
| Emergency medicine | 265 |
| Licensed clinical social worker | 245 |
| Obstetrics/gynecology | 209 |
| Diagnostic Radiology | 179 |
| Clinical psychologist | 175 |
| Chiropractic | 164 |
| Centralized Flu | 157 |
| Optometrist | 154 |
| Cardiology | 145 |
| Mental Health Counselors | 131 |
| Orthopedic surgery | 127 |
| General surgery | 111 |
| Podiatry | 111 |
| Ophthalmology | 111 |
| Anesthesiologist Assistant | 105 |
| Gastroenterology | 102 |
| Mass Immunization Roster Billers | 101 |
| Psychiatry | 98 |
| Dermatology | 93 |
| Neurology | 89 |
| Occupational therapist (private practice) | 81 |
| General practice | 77 |
| Hematology/oncology | 74 |
| Nephrology | 70 |
| Urology | 67 |
| Critical care (intensivists) | 65 |
| Physical medicine and rehabilitation | 64 |
| Pathology | 63 |
| Pulmonary disease | 60 |
| Otolaryngology | 53 |
| Endocrinology | 48 |
| Neurosurgery | 47 |
| Infectious disease | 47 |
| Hospitalist | 36 |
| Plastic and reconstructive surgery | 35 |
| Rheumatology | 35 |
| Pediatric medicine | 34 |
| Pain Management | 28 |
| Ambulatory Surgical Center | 28 |
| Speech / language pathology | 26 |
| Vascular surgery | 25 |
| Radiation oncology | 25 |
| Marriage and Family Therapist | 25 |
| Interventional Cardiology | 24 |
| Colorectal surgery (formerly proctology) | 22 |
| Thoracic surgery | 21 |
| Registered Dietician/Nutrition Professional | 20 |
| Interventional radiology | 19 |
| Pharmacy | 19 |
| Audiologist (billing independently) | 18 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 18 |
| Independent Diagnostic Testing Facility (IDTF) | 18 |
| Allergy/immunology | 17 |
| Cardiac Electrophysiology | 16 |
| Sports Medicine | 13 |
| Hospice and Palliative Care | 12 |
| Clinical Laboratory (Billing Independently) | 11 |
| Hand surgery | 11 |
| Interventional Pain Management (IPM) | 11 |
| Gynecologist/oncologist | 11 |
| Certified nurse midwife | 10 |
| Geriatric medicine | 10 |
| Surgical oncology | 10 |
| Oral surgery (dentists only) | 8 |
| Medical oncology | 8 |
| Advanced Heart Failure and Transplant Cardiology | 7 |
| Micrographic Dermatologic Surgery | 7 |
| Osteopathic manipulative therapy | 7 |
| Hematology | 6 |
| Opioid Treatment Program | 5 |
| Psychologist (billing independently) | 4 |
| Cardiac surgery | 4 |
| Maxillofacial surgery | 3 |
| Home Infusion Therapy Services | 2 |
| Medical Genetics and Genomics | 2 |
| Mammography Screening Center | 2 |
| Peripheral vascular disease | 2 |
| Certified clinical nurse specialist | 2 |
| Nuclear medicine | 2 |
| Neuropsychiatry | 1 |
| Unknown physician specialty | 1 |
| Portable X-Ray Supplier (Billing Independently) | 1 |
| Addiction medicine | 1 |
| Preventive medicine | 1 |
| Sleep Medicine | 1 |