| Nurse practitioner | 1,898 |
| Physician assistant | 837 |
| Family practice | 799 |
| Physical therapist (private practice) | 760 |
| Chiropractic | 748 |
| Licensed clinical social worker | 427 |
| Optometrist | 323 |
| Certified Registered Nurse Anesthetist (CRNA) | 313 |
| Mental Health Counselors | 302 |
| Internal medicine | 286 |
| Anesthesiology | 272 |
| Emergency medicine | 264 |
| Mass Immunization Roster Billers | 253 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 187 |
| Diagnostic Radiology | 171 |
| Obstetrics/gynecology | 163 |
| Hospitalist | 154 |
| General surgery | 153 |
| Psychiatry | 145 |
| Orthopedic surgery | 145 |
| Occupational therapist (private practice) | 144 |
| Podiatry | 115 |
| Clinical psychologist | 106 |
| Ophthalmology | 95 |
| Cardiology | 86 |
| Pathology | 78 |
| Neurology | 74 |
| Speech / language pathology | 72 |
| Gastroenterology | 68 |
| Pulmonary disease | 67 |
| Urology | 65 |
| Otolaryngology | 57 |
| Audiologist (billing independently) | 57 |
| Nephrology | 56 |
| Dermatology | 51 |
| Centralized Flu | 46 |
| Marriage and Family Therapist | 45 |
| Pediatric medicine | 42 |
| Certified nurse midwife | 41 |
| Physical medicine and rehabilitation | 39 |
| Infectious disease | 38 |
| Hematology/oncology | 34 |
| Medical oncology | 32 |
| Pharmacy | 32 |
| Rheumatology | 31 |
| Endocrinology | 29 |
| Registered Dietician/Nutrition Professional | 28 |
| Ambulatory Surgical Center | 27 |
| Interventional Cardiology | 26 |
| Radiation oncology | 26 |
| Neurosurgery | 26 |
| Plastic and reconstructive surgery | 25 |
| Vascular surgery | 22 |
| Critical care (intensivists) | 20 |
| Allergy/immunology | 18 |
| Oral surgery (dentists only) | 17 |
| Cardiac Electrophysiology | 15 |
| Thoracic surgery | 13 |
| Colorectal surgery (formerly proctology) | 13 |
| General practice | 12 |
| Cardiac surgery | 12 |
| Sleep Medicine | 11 |
| Hospice and Palliative Care | 11 |
| Interventional Pain Management (IPM) | 11 |
| Sports Medicine | 11 |
| Hand surgery | 11 |
| Pain Management | 11 |
| Clinical Laboratory (Billing Independently) | 10 |
| Epileptologists | 9 |
| Hematology | 8 |
| Surgical oncology | 7 |
| Interventional radiology | 7 |
| Independent Diagnostic Testing Facility (IDTF) | 7 |
| Gynecologist/oncologist | 6 |
| Nuclear medicine | 6 |
| Advanced Heart Failure and Transplant Cardiology | 6 |
| Medical Genetics and Genomics | 4 |
| Maxillofacial surgery | 4 |
| Preventive medicine | 4 |
| Certified clinical nurse specialist | 4 |
| Geriatric medicine | 2 |
| Osteopathic manipulative therapy | 2 |
| Unknown Provider | 2 |
| Single or Multispecialty Clinic or Group Practice | 2 |
| Hematopoietic Cell Transplantation and Cellular Therapy | 2 |
| Portable X-Ray Supplier (Billing Independently) | 2 |
| Opioid Treatment Program | 2 |
| Peripheral vascular disease | 2 |
| Medicare Diabetes Preventive Program | 2 |
| Slide Preparation Facilities | 1 |
| Micrographic Dermatologic Surgery | 1 |
| Addiction medicine | 1 |