| Nurse practitioner | 3,731 |
| Physician assistant | 1,902 |
| Internal medicine | 1,745 |
| Physical therapist (private practice) | 1,589 |
| Licensed clinical social worker | 1,144 |
| Family practice | 785 |
| Anesthesiology | 661 |
| Emergency medicine | 644 |
| Certified Registered Nurse Anesthetist (CRNA) | 587 |
| Mental Health Counselors | 556 |
| Diagnostic Radiology | 515 |
| Obstetrics/gynecology | 497 |
| Psychiatry | 416 |
| Optometrist | 349 |
| Orthopedic surgery | 332 |
| Hospitalist | 320 |
| Clinical psychologist | 319 |
| Cardiology | 318 |
| General surgery | 310 |
| Ophthalmology | 307 |
| Mass Immunization Roster Billers | 300 |
| Chiropractic | 275 |
| Neurology | 272 |
| Gastroenterology | 245 |
| Occupational therapist (private practice) | 240 |
| Podiatry | 216 |
| Pediatric medicine | 196 |
| Dermatology | 189 |
| Ambulatory Surgical Center | 176 |
| Pathology | 172 |
| Audiologist (billing independently) | 172 |
| Critical care (intensivists) | 163 |
| Nephrology | 155 |
| Urology | 153 |
| Centralized Flu | 139 |
| Otolaryngology | 136 |
| Physical medicine and rehabilitation | 136 |
| Endocrinology | 132 |
| Hematology/oncology | 124 |
| Pulmonary disease | 123 |
| Infectious disease | 116 |
| Registered Dietician/Nutrition Professional | 113 |
| Speech / language pathology | 98 |
| Certified nurse midwife | 96 |
| Rheumatology | 85 |
| Medical oncology | 79 |
| Neurosurgery | 75 |
| Vascular surgery | 71 |
| Radiation oncology | 70 |
| Plastic and reconstructive surgery | 63 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 63 |
| Opioid Treatment Program | 54 |
| Allergy/immunology | 52 |
| Pharmacy | 45 |
| Geriatric medicine | 43 |
| General practice | 39 |
| Clinical Laboratory (Billing Independently) | 37 |
| Interventional radiology | 36 |
| Pain Management | 31 |
| Interventional Pain Management (IPM) | 30 |
| Thoracic surgery | 29 |
| Hospice and Palliative Care | 24 |
| Interventional Cardiology | 23 |
| Independent Diagnostic Testing Facility (IDTF) | 20 |
| Cardiac surgery | 20 |
| Hand surgery | 19 |
| Cardiac Electrophysiology | 19 |
| Sports Medicine | 18 |
| Colorectal surgery (formerly proctology) | 17 |
| Maxillofacial surgery | 15 |
| Marriage and Family Therapist | 15 |
| Certified clinical nurse specialist | 15 |
| Anesthesiologist Assistant | 14 |
| Surgical oncology | 14 |
| Neuropsychiatry | 13 |
| Sleep Medicine | 13 |
| Gynecologist/oncologist | 12 |
| Oral surgery (dentists only) | 11 |
| Nuclear medicine | 11 |
| Advanced Heart Failure and Transplant Cardiology | 10 |
| Hematology | 9 |
| Micrographic Dermatologic Surgery | 8 |
| Preventive medicine | 6 |
| Medical Genetics and Genomics | 6 |
| Home Infusion Therapy Services | 5 |
| Dentist | 5 |
| Medicare Diabetes Preventive Program | 4 |
| Osteopathic manipulative therapy | 4 |
| Psychologist (billing independently) | 4 |
| Portable X-Ray Supplier (Billing Independently) | 4 |
| Single or Multispecialty Clinic or Group Practice | 2 |
| Epileptologists | 2 |
| General Psychiatry | 2 |
| Addiction medicine | 2 |
| Hematopoietic Cell Transplantation and Cellular Therapy | 1 |
| Unknown Provider | 1 |
| Peripheral vascular disease | 1 |
| Undersea and Hyperbaric Medicine | 1 |