| Nurse practitioner | 13,191 |
| Physician assistant | 4,620 |
| Internal medicine | 3,589 |
| Family practice | 3,516 |
| Certified Registered Nurse Anesthetist (CRNA) | 2,814 |
| Emergency medicine | 2,073 |
| Physical therapist (private practice) | 2,021 |
| Licensed clinical social worker | 1,919 |
| Mental Health Counselors | 1,603 |
| Anesthesiology | 1,541 |
| Optometrist | 1,450 |
| Diagnostic Radiology | 1,365 |
| Chiropractic | 1,364 |
| Obstetrics/gynecology | 1,269 |
| Mass Immunization Roster Billers | 1,215 |
| Clinical psychologist | 963 |
| General surgery | 926 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 887 |
| Psychiatry | 875 |
| Orthopedic surgery | 861 |
| Cardiology | 813 |
| Hospitalist | 784 |
| Neurology | 732 |
| Podiatry | 706 |
| Ophthalmology | 610 |
| Gastroenterology | 596 |
| Pathology | 561 |
| Pulmonary disease | 539 |
| Pediatric medicine | 461 |
| Dermatology | 428 |
| Occupational therapist (private practice) | 405 |
| Anesthesiologist Assistant | 398 |
| Hematology/oncology | 397 |
| Audiologist (billing independently) | 394 |
| Urology | 382 |
| Nephrology | 367 |
| Otolaryngology | 367 |
| Physical medicine and rehabilitation | 342 |
| Infectious disease | 272 |
| Endocrinology | 269 |
| Certified nurse midwife | 262 |
| Critical care (intensivists) | 238 |
| Centralized Flu | 233 |
| Certified clinical nurse specialist | 221 |
| Radiation oncology | 219 |
| Speech / language pathology | 217 |
| Neurosurgery | 208 |
| Rheumatology | 208 |
| Registered Dietician/Nutrition Professional | 199 |
| Ambulatory Surgical Center | 185 |
| Plastic and reconstructive surgery | 183 |
| Interventional Cardiology | 179 |
| Vascular surgery | 172 |
| Medical oncology | 138 |
| Allergy/immunology | 131 |
| Cardiac Electrophysiology | 130 |
| Pain Management | 123 |
| Sports Medicine | 115 |
| Thoracic surgery | 110 |
| Hospice and Palliative Care | 99 |
| Pharmacy | 83 |
| General practice | 82 |
| Colorectal surgery (formerly proctology) | 81 |
| Interventional radiology | 73 |
| Hematology | 71 |
| Geriatric medicine | 68 |
| Hand surgery | 67 |
| Cardiac surgery | 61 |
| Sleep Medicine | 60 |
| Advanced Heart Failure and Transplant Cardiology | 54 |
| Opioid Treatment Program | 54 |
| Surgical oncology | 50 |
| Clinical Laboratory (Billing Independently) | 48 |
| Independent Diagnostic Testing Facility (IDTF) | 47 |
| Gynecologist/oncologist | 46 |
| Interventional Pain Management (IPM) | 35 |
| Marriage and Family Therapist | 35 |
| Addiction medicine | 33 |
| Single or Multispecialty Clinic or Group Practice | 33 |
| Maxillofacial surgery | 30 |
| Oral surgery (dentists only) | 28 |
| Osteopathic manipulative therapy | 20 |
| Nuclear medicine | 19 |
| Public Health or Welfare Agencies (Federal, State, and local) | 16 |
| Unknown Provider | 14 |
| Micrographic Dermatologic Surgery | 14 |
| Epileptologists | 14 |
| Medical Genetics and Genomics | 13 |
| Preventive medicine | 13 |
| Dentist | 13 |
| Peripheral vascular disease | 10 |
| Unknown physician specialty | 7 |
| Portable X-Ray Supplier (Billing Independently) | 7 |
| Hematopoietic Cell Transplantation and Cellular Therapy | 6 |
| Adult Congenital Heart Disease | 5 |
| Home Infusion Therapy Services | 4 |
| Neuropsychiatry | 4 |
| Medicare Diabetes Preventive Program | 4 |
| Oral and Maxillofacial Pathology | 3 |
| Psychologist (billing independently) | 2 |
| Prosthodontics | 2 |
| General Psychiatry | 2 |
| Undersea and Hyperbaric Medicine | 1 |
| Radiation Therapy Centers | 1 |
| Medical Toxicology | 1 |
| Orofacial Pain | 1 |