| Nurse practitioner | 4,524 |
| Physician assistant | 3,507 |
| Licensed clinical social worker | 2,546 |
| Family practice | 2,163 |
| Internal medicine | 2,151 |
| Physical therapist (private practice) | 1,970 |
| Certified Registered Nurse Anesthetist (CRNA) | 1,604 |
| Emergency medicine | 1,205 |
| Chiropractic | 1,181 |
| Mental Health Counselors | 910 |
| Anesthesiology | 741 |
| Obstetrics/gynecology | 718 |
| Optometrist | 710 |
| Clinical psychologist | 679 |
| Diagnostic Radiology | 641 |
| Psychiatry | 619 |
| Mass Immunization Roster Billers | 526 |
| General surgery | 476 |
| Orthopedic surgery | 453 |
| Cardiology | 412 |
| Podiatry | 401 |
| Ophthalmology | 399 |
| Neurology | 370 |
| Occupational therapist (private practice) | 347 |
| Pathology | 265 |
| Gastroenterology | 264 |
| Physical medicine and rehabilitation | 249 |
| Pediatric medicine | 247 |
| Dermatology | 239 |
| Hospitalist | 230 |
| Pulmonary disease | 224 |
| Otolaryngology | 203 |
| Urology | 191 |
| Audiologist (billing independently) | 185 |
| Nephrology | 167 |
| Hematology/oncology | 158 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 158 |
| Centralized Flu | 148 |
| Infectious disease | 144 |
| Endocrinology | 121 |
| Neurosurgery | 119 |
| Certified nurse midwife | 117 |
| Speech / language pathology | 104 |
| Radiation oncology | 100 |
| Interventional Cardiology | 98 |
| Allergy/immunology | 92 |
| Plastic and reconstructive surgery | 90 |
| Rheumatology | 89 |
| Ambulatory Surgical Center | 85 |
| Vascular surgery | 79 |
| Pharmacy | 78 |
| Critical care (intensivists) | 73 |
| Thoracic surgery | 72 |
| Interventional radiology | 58 |
| General practice | 57 |
| Medical oncology | 56 |
| Pain Management | 51 |
| Colorectal surgery (formerly proctology) | 48 |
| Cardiac Electrophysiology | 47 |
| Geriatric medicine | 46 |
| Sports Medicine | 42 |
| Clinical Laboratory (Billing Independently) | 36 |
| Hand surgery | 34 |
| Maxillofacial surgery | 33 |
| Registered Dietician/Nutrition Professional | 33 |
| Oral surgery (dentists only) | 32 |
| Osteopathic manipulative therapy | 31 |
| Hospice and Palliative Care | 29 |
| Opioid Treatment Program | 27 |
| Sleep Medicine | 23 |
| Anesthesiologist Assistant | 22 |
| Marriage and Family Therapist | 21 |
| Independent Diagnostic Testing Facility (IDTF) | 21 |
| Hematology | 20 |
| Gynecologist/oncologist | 18 |
| Interventional Pain Management (IPM) | 18 |
| Cardiac surgery | 16 |
| Advanced Heart Failure and Transplant Cardiology | 14 |
| Surgical oncology | 13 |
| Addiction medicine | 11 |
| Nuclear medicine | 10 |
| Epileptologists | 10 |
| Certified clinical nurse specialist | 9 |
| Micrographic Dermatologic Surgery | 8 |
| Medical Genetics and Genomics | 7 |
| Preventive medicine | 7 |
| Home Infusion Therapy Services | 5 |
| Neuropsychiatry | 4 |
| Dentist | 3 |
| General Psychiatry | 3 |
| Psychologist (billing independently) | 3 |
| Hematopoietic Cell Transplantation and Cellular Therapy | 2 |
| Undersea and Hyperbaric Medicine | 2 |
| Oral and Maxillofacial Pathology | 2 |
| Unknown Provider | 2 |
| Medicare Diabetes Preventive Program | 1 |
| Radiation Therapy Centers | 1 |
| Adult Congenital Heart Disease | 1 |
| Portable X-Ray Supplier (Billing Independently) | 1 |