| Nurse practitioner | 20,425 |
| Physician assistant | 8,356 |
| Internal medicine | 7,384 |
| Family practice | 5,409 |
| Certified Registered Nurse Anesthetist (CRNA) | 4,950 |
| Physical therapist (private practice) | 4,147 |
| Emergency medicine | 3,560 |
| Anesthesiology | 2,783 |
| Licensed clinical social worker | 2,654 |
| Diagnostic Radiology | 2,432 |
| Chiropractic | 2,308 |
| Obstetrics/gynecology | 2,108 |
| Mental Health Counselors | 1,933 |
| Optometrist | 1,889 |
| Centralized Flu | 1,631 |
| Cardiology | 1,584 |
| Clinical psychologist | 1,445 |
| Orthopedic surgery | 1,437 |
| General surgery | 1,352 |
| Psychiatry | 1,341 |
| Mass Immunization Roster Billers | 1,337 |
| Hospitalist | 1,295 |
| Ophthalmology | 1,278 |
| Podiatry | 1,266 |
| Neurology | 1,257 |
| Gastroenterology | 1,193 |
| General practice | 1,167 |
| Dermatology | 1,061 |
| Occupational therapist (private practice) | 1,025 |
| Anesthesiologist Assistant | 848 |
| Pathology | 803 |
| Pulmonary disease | 753 |
| Urology | 752 |
| Hematology/oncology | 736 |
| Nephrology | 620 |
| Otolaryngology | 605 |
| Physical medicine and rehabilitation | 594 |
| Critical care (intensivists) | 551 |
| Infectious disease | 547 |
| Ambulatory Surgical Center | 516 |
| Pediatric medicine | 509 |
| Audiologist (billing independently) | 447 |
| Endocrinology | 446 |
| Speech / language pathology | 432 |
| Neurosurgery | 426 |
| Interventional Cardiology | 411 |
| Radiation oncology | 394 |
| Rheumatology | 362 |
| Plastic and reconstructive surgery | 338 |
| Vascular surgery | 289 |
| Pain Management | 274 |
| Registered Dietician/Nutrition Professional | 241 |
| Thoracic surgery | 241 |
| Certified nurse midwife | 241 |
| Medical oncology | 238 |
| Cardiac Electrophysiology | 224 |
| Marriage and Family Therapist | 217 |
| Interventional Pain Management (IPM) | 214 |
| Interventional radiology | 207 |
| Allergy/immunology | 202 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 202 |
| Pharmacy | 192 |
| Independent Diagnostic Testing Facility (IDTF) | 191 |
| Clinical Laboratory (Billing Independently) | 188 |
| Colorectal surgery (formerly proctology) | 141 |
| Hand surgery | 132 |
| Hospice and Palliative Care | 127 |
| Sports Medicine | 126 |
| Surgical oncology | 96 |
| Gynecologist/oncologist | 85 |
| Geriatric medicine | 81 |
| Osteopathic manipulative therapy | 69 |
| Oral surgery (dentists only) | 68 |
| Cardiac surgery | 66 |
| Opioid Treatment Program | 60 |
| Advanced Heart Failure and Transplant Cardiology | 50 |
| Psychologist (billing independently) | 49 |
| Hematology | 47 |
| Sleep Medicine | 40 |
| Micrographic Dermatologic Surgery | 40 |
| Maxillofacial surgery | 36 |
| Neuropsychiatry | 26 |
| Nuclear medicine | 25 |
| Preventive medicine | 23 |
| Medical Genetics and Genomics | 22 |
| Portable X-Ray Supplier (Billing Independently) | 19 |
| Addiction medicine | 15 |
| Epileptologists | 14 |
| Home Infusion Therapy Services | 13 |
| General Psychiatry | 12 |
| Certified clinical nurse specialist | 11 |
| Hematopoietic Cell Transplantation and Cellular Therapy | 9 |
| Peripheral vascular disease | 7 |
| Undersea and Hyperbaric Medicine | 6 |
| Medicare Diabetes Preventive Program | 6 |
| Single or Multispecialty Clinic or Group Practice | 6 |
| Unknown physician specialty | 5 |
| Dentist | 4 |
| Unknown Provider | 4 |
| All other suppliers, e.g., Drug Stores | 4 |
| Mammography Screening Center | 3 |
| Oral Medicine | 3 |
| Oral and Maxillofacial Radiology | 2 |
| Oral and Maxillofacial Pathology | 1 |
| Intensive Cardiac Rehabilitation | 1 |