| Nurse practitioner | 3,938 |
| Physician assistant | 1,013 |
| Family practice | 820 |
| Certified Registered Nurse Anesthetist (CRNA) | 805 |
| Internal medicine | 741 |
| Physical therapist (private practice) | 657 |
| Licensed clinical social worker | 518 |
| Emergency medicine | 442 |
| Optometrist | 393 |
| Mental Health Counselors | 342 |
| Chiropractic | 322 |
| Mass Immunization Roster Billers | 319 |
| Anesthesiology | 298 |
| Obstetrics/gynecology | 289 |
| Diagnostic Radiology | 269 |
| General surgery | 222 |
| Orthopedic surgery | 208 |
| Psychiatry | 174 |
| Hospitalist | 174 |
| Cardiology | 154 |
| Occupational therapist (private practice) | 137 |
| Neurology | 135 |
| Pediatric medicine | 127 |
| Clinical psychologist | 123 |
| Ophthalmology | 123 |
| Podiatry | 121 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 115 |
| Pulmonary disease | 114 |
| Gastroenterology | 112 |
| Pathology | 109 |
| Hematology/oncology | 98 |
| Audiologist (billing independently) | 91 |
| Urology | 89 |
| Centralized Flu | 88 |
| Dermatology | 85 |
| Otolaryngology | 85 |
| Nephrology | 84 |
| Speech / language pathology | 69 |
| Neurosurgery | 61 |
| Physical medicine and rehabilitation | 58 |
| Radiation oncology | 55 |
| Pharmacy | 53 |
| Interventional Cardiology | 49 |
| Infectious disease | 46 |
| Endocrinology | 46 |
| Vascular surgery | 45 |
| Rheumatology | 40 |
| Certified nurse midwife | 38 |
| Allergy/immunology | 36 |
| Plastic and reconstructive surgery | 36 |
| Clinical Laboratory (Billing Independently) | 31 |
| General practice | 30 |
| Thoracic surgery | 30 |
| Registered Dietician/Nutrition Professional | 29 |
| Marriage and Family Therapist | 29 |
| Pain Management | 29 |
| Medical oncology | 27 |
| Ambulatory Surgical Center | 26 |
| Critical care (intensivists) | 25 |
| Cardiac Electrophysiology | 24 |
| Hospice and Palliative Care | 22 |
| Opioid Treatment Program | 20 |
| Interventional Pain Management (IPM) | 19 |
| Sports Medicine | 16 |
| Surgical oncology | 16 |
| Interventional radiology | 15 |
| Cardiac surgery | 14 |
| Hand surgery | 14 |
| Oral surgery (dentists only) | 13 |
| Certified clinical nurse specialist | 13 |
| Sleep Medicine | 12 |
| Geriatric medicine | 11 |
| Colorectal surgery (formerly proctology) | 10 |
| Independent Diagnostic Testing Facility (IDTF) | 10 |
| Single or Multispecialty Clinic or Group Practice | 10 |
| Maxillofacial surgery | 8 |
| Neuropsychiatry | 8 |
| Addiction medicine | 8 |
| Advanced Heart Failure and Transplant Cardiology | 7 |
| Gynecologist/oncologist | 6 |
| Hematology | 6 |
| Psychologist (billing independently) | 4 |
| Dentist | 4 |
| Preventive medicine | 3 |
| Unknown Provider | 3 |
| Nuclear medicine | 3 |
| Home Infusion Therapy Services | 2 |
| Micrographic Dermatologic Surgery | 2 |
| Radiation Therapy Centers | 1 |
| General Psychiatry | 1 |
| Unknown physician specialty | 1 |
| Osteopathic manipulative therapy | 1 |
| Portable X-Ray Supplier (Billing Independently) | 1 |
| Medicare Diabetes Preventive Program | 1 |
| Medical Genetics and Genomics | 1 |