| Nurse practitioner | 9,115 |
| Physician assistant | 7,499 |
| Internal medicine | 5,325 |
| Physical therapist (private practice) | 5,022 |
| Licensed clinical social worker | 3,628 |
| Family practice | 2,648 |
| Anesthesiology | 2,442 |
| Emergency medicine | 2,222 |
| Psychiatry | 1,787 |
| Diagnostic Radiology | 1,773 |
| Obstetrics/gynecology | 1,653 |
| Clinical psychologist | 1,466 |
| Certified Registered Nurse Anesthetist (CRNA) | 1,406 |
| Cardiology | 1,326 |
| Chiropractic | 1,112 |
| Hospitalist | 1,090 |
| Podiatry | 1,058 |
| Mass Immunization Roster Billers | 1,053 |
| Optometrist | 1,051 |
| Neurology | 1,043 |
| Occupational therapist (private practice) | 994 |
| Ophthalmology | 979 |
| General surgery | 955 |
| Gastroenterology | 921 |
| Orthopedic surgery | 901 |
| Mental Health Counselors | 862 |
| Pathology | 764 |
| Dermatology | 668 |
| Pulmonary disease | 554 |
| Physical medicine and rehabilitation | 551 |
| Urology | 526 |
| Otolaryngology | 490 |
| Nephrology | 476 |
| Pediatric medicine | 468 |
| Endocrinology | 451 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 423 |
| Hematology/oncology | 419 |
| Audiologist (billing independently) | 402 |
| Infectious disease | 393 |
| Speech / language pathology | 365 |
| Medical oncology | 352 |
| Centralized Flu | 297 |
| Critical care (intensivists) | 278 |
| Rheumatology | 270 |
| Neurosurgery | 267 |
| Plastic and reconstructive surgery | 261 |
| Registered Dietician/Nutrition Professional | 259 |
| Certified nurse midwife | 224 |
| Radiation oncology | 223 |
| Vascular surgery | 213 |
| Allergy/immunology | 193 |
| Pharmacy | 164 |
| Interventional Cardiology | 163 |
| Interventional radiology | 149 |
| Pain Management | 143 |
| Geriatric medicine | 130 |
| Thoracic surgery | 126 |
| General practice | 119 |
| Hospice and Palliative Care | 115 |
| Cardiac Electrophysiology | 112 |
| Colorectal surgery (formerly proctology) | 108 |
| Ambulatory Surgical Center | 106 |
| Clinical Laboratory (Billing Independently) | 80 |
| Sports Medicine | 80 |
| Surgical oncology | 74 |
| Hematology | 69 |
| Hand surgery | 68 |
| Cardiac surgery | 65 |
| Oral surgery (dentists only) | 64 |
| Gynecologist/oncologist | 64 |
| Nuclear medicine | 57 |
| Advanced Heart Failure and Transplant Cardiology | 54 |
| Marriage and Family Therapist | 47 |
| Interventional Pain Management (IPM) | 46 |
| Independent Diagnostic Testing Facility (IDTF) | 44 |
| Opioid Treatment Program | 39 |
| Osteopathic manipulative therapy | 38 |
| Maxillofacial surgery | 33 |
| Sleep Medicine | 29 |
| Addiction medicine | 19 |
| Neuropsychiatry | 18 |
| Preventive medicine | 16 |
| Dentist | 15 |
| Certified clinical nurse specialist | 15 |
| Micrographic Dermatologic Surgery | 14 |
| Medical Genetics and Genomics | 14 |
| Hematopoietic Cell Transplantation and Cellular Therapy | 11 |
| Single or Multispecialty Clinic or Group Practice | 11 |
| Portable X-Ray Supplier (Billing Independently) | 9 |
| Unknown physician specialty | 8 |
| Medical Toxicology | 8 |
| General Psychiatry | 8 |
| Undersea and Hyperbaric Medicine | 6 |
| Adult Congenital Heart Disease | 6 |
| Home Infusion Therapy Services | 5 |
| Epileptologists | 4 |
| Oral and Maxillofacial Pathology | 3 |
| Medicare Diabetes Preventive Program | 2 |
| Intensive Cardiac Rehabilitation | 2 |
| Psychologist (billing independently) | 2 |
| Radiation Therapy Centers | 2 |
| Unknown Provider | 1 |
| Anesthesiologist Assistant | 1 |
| All other suppliers, e.g., Drug Stores | 1 |