| Nurse practitioner | 5,726 |
| Physician assistant | 4,835 |
| Certified Registered Nurse Anesthetist (CRNA) | 2,007 |
| Physical therapist (private practice) | 2,007 |
| Family practice | 1,940 |
| Internal medicine | 1,823 |
| Licensed clinical social worker | 1,185 |
| Emergency medicine | 1,019 |
| Obstetrics/gynecology | 795 |
| Anesthesiology | 759 |
| Optometrist | 715 |
| Mental Health Counselors | 695 |
| Mass Immunization Roster Billers | 692 |
| Chiropractic | 675 |
| Diagnostic Radiology | 628 |
| Hospitalist | 628 |
| General surgery | 540 |
| Orthopedic surgery | 513 |
| Psychiatry | 491 |
| Cardiology | 419 |
| Neurology | 371 |
| Clinical psychologist | 352 |
| Ophthalmology | 344 |
| Occupational therapist (private practice) | 339 |
| Gastroenterology | 320 |
| Dermatology | 272 |
| Pulmonary disease | 250 |
| Hematology/oncology | 241 |
| Pathology | 231 |
| Centralized Flu | 223 |
| Audiologist (billing independently) | 216 |
| Podiatry | 215 |
| Nephrology | 213 |
| Otolaryngology | 211 |
| Urology | 201 |
| Pediatric medicine | 191 |
| Registered Dietician/Nutrition Professional | 188 |
| Physical medicine and rehabilitation | 167 |
| Certified nurse midwife | 153 |
| Speech / language pathology | 149 |
| Infectious disease | 148 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 131 |
| Endocrinology | 125 |
| Radiation oncology | 116 |
| Rheumatology | 114 |
| Neurosurgery | 96 |
| Medical oncology | 92 |
| Interventional Cardiology | 92 |
| Ambulatory Surgical Center | 91 |
| Plastic and reconstructive surgery | 89 |
| Vascular surgery | 80 |
| Pharmacy | 73 |
| Critical care (intensivists) | 72 |
| Allergy/immunology | 61 |
| Marriage and Family Therapist | 59 |
| Cardiac Electrophysiology | 54 |
| Sports Medicine | 53 |
| Anesthesiologist Assistant | 50 |
| Opioid Treatment Program | 50 |
| Geriatric medicine | 49 |
| Hospice and Palliative Care | 47 |
| Interventional radiology | 47 |
| Clinical Laboratory (Billing Independently) | 46 |
| Thoracic surgery | 44 |
| Pain Management | 43 |
| Independent Diagnostic Testing Facility (IDTF) | 40 |
| Interventional Pain Management (IPM) | 31 |
| General practice | 31 |
| Hand surgery | 30 |
| Cardiac surgery | 30 |
| Surgical oncology | 29 |
| Hematology | 28 |
| Gynecologist/oncologist | 25 |
| Advanced Heart Failure and Transplant Cardiology | 23 |
| Micrographic Dermatologic Surgery | 23 |
| Oral surgery (dentists only) | 19 |
| Colorectal surgery (formerly proctology) | 13 |
| Dentist | 13 |
| Sleep Medicine | 12 |
| Osteopathic manipulative therapy | 11 |
| Maxillofacial surgery | 10 |
| Unknown Provider | 10 |
| Psychologist (billing independently) | 9 |
| Certified clinical nurse specialist | 8 |
| Addiction medicine | 6 |
| Peripheral vascular disease | 5 |
| Neuropsychiatry | 5 |
| Hematopoietic Cell Transplantation and Cellular Therapy | 5 |
| Home Infusion Therapy Services | 5 |
| Unknown physician specialty | 4 |
| Single or Multispecialty Clinic or Group Practice | 3 |
| Medical Toxicology | 3 |
| Portable X-Ray Supplier (Billing Independently) | 3 |
| Preventive medicine | 3 |
| Undersea and Hyperbaric Medicine | 2 |
| Mammography Screening Center | 1 |
| All other suppliers, e.g., Drug Stores | 1 |
| Adult Congenital Heart Disease | 1 |
| Medical Genetics and Genomics | 1 |