| Nurse practitioner | 11,991 |
| Physician assistant | 4,984 |
| Family practice | 4,748 |
| Internal medicine | 4,529 |
| Certified Registered Nurse Anesthetist (CRNA) | 2,987 |
| Physical therapist (private practice) | 2,918 |
| Emergency medicine | 2,661 |
| Anesthesiology | 2,374 |
| Optometrist | 1,918 |
| Obstetrics/gynecology | 1,566 |
| Diagnostic Radiology | 1,548 |
| Mental Health Counselors | 1,512 |
| Mass Immunization Roster Billers | 1,398 |
| Chiropractic | 1,251 |
| Licensed clinical social worker | 1,182 |
| Orthopedic surgery | 1,072 |
| General surgery | 1,052 |
| Psychiatry | 954 |
| Cardiology | 934 |
| Ophthalmology | 787 |
| Gastroenterology | 781 |
| Neurology | 761 |
| Clinical psychologist | 754 |
| Pathology | 722 |
| Hospitalist | 710 |
| Podiatry | 694 |
| Dermatology | 682 |
| Pediatric medicine | 606 |
| Nephrology | 553 |
| Pulmonary disease | 486 |
| Otolaryngology | 454 |
| Centralized Flu | 447 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 418 |
| Urology | 418 |
| Occupational therapist (private practice) | 412 |
| Physical medicine and rehabilitation | 405 |
| Hematology/oncology | 404 |
| Audiologist (billing independently) | 366 |
| Endocrinology | 342 |
| Interventional Cardiology | 333 |
| Infectious disease | 321 |
| Ambulatory Surgical Center | 312 |
| Neurosurgery | 299 |
| Registered Dietician/Nutrition Professional | 269 |
| Rheumatology | 266 |
| Anesthesiologist Assistant | 260 |
| Medical oncology | 255 |
| Plastic and reconstructive surgery | 248 |
| Speech / language pathology | 240 |
| Critical care (intensivists) | 237 |
| Radiation oncology | 232 |
| Pharmacy | 200 |
| Vascular surgery | 181 |
| Independent Diagnostic Testing Facility (IDTF) | 181 |
| Pain Management | 179 |
| Allergy/immunology | 178 |
| Thoracic surgery | 166 |
| Clinical Laboratory (Billing Independently) | 152 |
| General practice | 148 |
| Certified clinical nurse specialist | 124 |
| Interventional Pain Management (IPM) | 123 |
| Colorectal surgery (formerly proctology) | 122 |
| Cardiac Electrophysiology | 117 |
| Hospice and Palliative Care | 101 |
| Marriage and Family Therapist | 100 |
| Interventional radiology | 100 |
| Surgical oncology | 85 |
| Geriatric medicine | 79 |
| Hand surgery | 73 |
| Sports Medicine | 73 |
| Certified nurse midwife | 64 |
| Gynecologist/oncologist | 56 |
| Oral surgery (dentists only) | 47 |
| Cardiac surgery | 39 |
| Maxillofacial surgery | 35 |
| Portable X-Ray Supplier (Billing Independently) | 31 |
| Hematology | 29 |
| Opioid Treatment Program | 29 |
| Advanced Heart Failure and Transplant Cardiology | 27 |
| Sleep Medicine | 26 |
| Preventive medicine | 23 |
| Dentist | 21 |
| Nuclear medicine | 20 |
| Osteopathic manipulative therapy | 18 |
| Micrographic Dermatologic Surgery | 16 |
| Medical Genetics and Genomics | 15 |
| Hematopoietic Cell Transplantation and Cellular Therapy | 13 |
| Undersea and Hyperbaric Medicine | 10 |
| Psychologist (billing independently) | 8 |
| Single or Multispecialty Clinic or Group Practice | 8 |
| Addiction medicine | 7 |
| Epileptologists | 7 |
| General Psychiatry | 6 |
| Home Infusion Therapy Services | 4 |
| Neuropsychiatry | 3 |
| Medicare Diabetes Preventive Program | 3 |
| Oral and Maxillofacial Pathology | 2 |
| Public Health or Welfare Agencies (Federal, State, and local) | 2 |
| Unknown Provider | 1 |
| Peripheral vascular disease | 1 |