| Nurse practitioner | 1,565 |
| Physician assistant | 522 |
| Family practice | 489 |
| Internal medicine | 409 |
| Physical therapist (private practice) | 368 |
| Emergency medicine | 258 |
| Certified Registered Nurse Anesthetist (CRNA) | 253 |
| Licensed clinical social worker | 248 |
| Anesthesiology | 225 |
| Optometrist | 209 |
| Diagnostic Radiology | 193 |
| Obstetrics/gynecology | 170 |
| Hospitalist | 166 |
| Chiropractic | 154 |
| Mass Immunization Roster Billers | 149 |
| Mental Health Counselors | 130 |
| Psychiatry | 113 |
| Clinical psychologist | 108 |
| Neurology | 103 |
| General surgery | 102 |
| Orthopedic surgery | 101 |
| Cardiology | 84 |
| Ophthalmology | 82 |
| Gastroenterology | 82 |
| Pulmonary disease | 82 |
| Pathology | 72 |
| Occupational therapist (private practice) | 70 |
| Dermatology | 66 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 65 |
| Podiatry | 65 |
| Urology | 58 |
| Nephrology | 50 |
| Physical medicine and rehabilitation | 48 |
| Audiologist (billing independently) | 48 |
| Anesthesiologist Assistant | 46 |
| Medical oncology | 46 |
| Hematology | 37 |
| Otolaryngology | 37 |
| Infectious disease | 36 |
| Neurosurgery | 32 |
| Radiation oncology | 31 |
| Endocrinology | 31 |
| Plastic and reconstructive surgery | 30 |
| Pediatric medicine | 28 |
| Speech / language pathology | 28 |
| Registered Dietician/Nutrition Professional | 26 |
| Centralized Flu | 26 |
| Ambulatory Surgical Center | 24 |
| Hospice and Palliative Care | 23 |
| Sports Medicine | 23 |
| Allergy/immunology | 21 |
| Rheumatology | 21 |
| Hematology/oncology | 21 |
| Critical care (intensivists) | 20 |
| Interventional Cardiology | 19 |
| Certified nurse midwife | 18 |
| Sleep Medicine | 18 |
| Vascular surgery | 17 |
| Interventional radiology | 15 |
| Cardiac Electrophysiology | 14 |
| General practice | 13 |
| Colorectal surgery (formerly proctology) | 13 |
| Advanced Heart Failure and Transplant Cardiology | 11 |
| Surgical oncology | 11 |
| Thoracic surgery | 11 |
| Pain Management | 10 |
| Pharmacy | 10 |
| Certified clinical nurse specialist | 10 |
| Gynecologist/oncologist | 9 |
| Addiction medicine | 8 |
| Hand surgery | 7 |
| Cardiac surgery | 6 |
| Independent Diagnostic Testing Facility (IDTF) | 6 |
| Interventional Pain Management (IPM) | 5 |
| Maxillofacial surgery | 5 |
| Clinical Laboratory (Billing Independently) | 5 |
| Geriatric medicine | 4 |
| Hematopoietic Cell Transplantation and Cellular Therapy | 3 |
| Opioid Treatment Program | 3 |
| Adult Congenital Heart Disease | 3 |
| Epileptologists | 3 |
| Single or Multispecialty Clinic or Group Practice | 3 |
| Preventive medicine | 2 |
| Osteopathic manipulative therapy | 2 |
| Public Health or Welfare Agencies (Federal, State, and local) | 2 |
| Oral surgery (dentists only) | 2 |
| Unknown Provider | 1 |
| Micrographic Dermatologic Surgery | 1 |
| Medical Genetics and Genomics | 1 |
| Unknown physician specialty | 1 |
| Nuclear medicine | 1 |
| Home Infusion Therapy Services | 1 |
| Marriage and Family Therapist | 1 |