| Nurse practitioner | 8,892 |
| Physician assistant | 7,447 |
| Physical therapist (private practice) | 3,136 |
| Certified Registered Nurse Anesthetist (CRNA) | 3,005 |
| Family practice | 3,000 |
| Internal medicine | 2,787 |
| Licensed clinical social worker | 1,848 |
| Emergency medicine | 1,602 |
| Obstetrics/gynecology | 1,219 |
| Anesthesiology | 1,156 |
| Optometrist | 1,090 |
| Mental Health Counselors | 1,074 |
| Mass Immunization Roster Billers | 1,064 |
| Chiropractic | 1,032 |
| Diagnostic Radiology | 992 |
| Hospitalist | 957 |
| General surgery | 825 |
| Psychiatry | 789 |
| Orthopedic surgery | 787 |
| Cardiology | 646 |
| Neurology | 557 |
| Clinical psychologist | 547 |
| Ophthalmology | 531 |
| Occupational therapist (private practice) | 529 |
| Gastroenterology | 507 |
| Dermatology | 405 |
| Pulmonary disease | 365 |
| Pathology | 360 |
| Hematology/oncology | 358 |
| Urology | 340 |
| Centralized Flu | 334 |
| Podiatry | 331 |
| Audiologist (billing independently) | 324 |
| Nephrology | 317 |
| Otolaryngology | 312 |
| Pediatric medicine | 299 |
| Registered Dietician/Nutrition Professional | 297 |
| Physical medicine and rehabilitation | 242 |
| Certified nurse midwife | 231 |
| Infectious disease | 228 |
| Speech / language pathology | 220 |
| Ambulance Service Supplier, e.g., private ambulance companies, funeral homes | 196 |
| Endocrinology | 191 |
| Radiation oncology | 174 |
| Rheumatology | 168 |
| Neurosurgery | 156 |
| Ambulatory Surgical Center | 145 |
| Interventional Cardiology | 141 |
| Medical oncology | 138 |
| Plastic and reconstructive surgery | 126 |
| Vascular surgery | 123 |
| Pharmacy | 117 |
| Critical care (intensivists) | 113 |
| Allergy/immunology | 103 |
| Marriage and Family Therapist | 86 |
| Geriatric medicine | 86 |
| Cardiac Electrophysiology | 85 |
| Interventional radiology | 81 |
| Sports Medicine | 80 |
| Clinical Laboratory (Billing Independently) | 74 |
| Anesthesiologist Assistant | 74 |
| Opioid Treatment Program | 71 |
| Thoracic surgery | 68 |
| Hospice and Palliative Care | 63 |
| Independent Diagnostic Testing Facility (IDTF) | 62 |
| Pain Management | 59 |
| General practice | 58 |
| Interventional Pain Management (IPM) | 48 |
| Hand surgery | 46 |
| Advanced Heart Failure and Transplant Cardiology | 42 |
| Hematology | 42 |
| Surgical oncology | 39 |
| Cardiac surgery | 39 |
| Gynecologist/oncologist | 38 |
| Micrographic Dermatologic Surgery | 31 |
| Sleep Medicine | 24 |
| Oral surgery (dentists only) | 23 |
| Colorectal surgery (formerly proctology) | 22 |
| Dentist | 17 |
| Psychologist (billing independently) | 17 |
| Maxillofacial surgery | 17 |
| Osteopathic manipulative therapy | 17 |
| Certified clinical nurse specialist | 11 |
| Unknown Provider | 11 |
| Addiction medicine | 10 |
| Hematopoietic Cell Transplantation and Cellular Therapy | 9 |
| Neuropsychiatry | 8 |
| Home Infusion Therapy Services | 7 |
| Preventive medicine | 7 |
| Peripheral vascular disease | 5 |
| Unknown physician specialty | 5 |
| Undersea and Hyperbaric Medicine | 3 |
| Single or Multispecialty Clinic or Group Practice | 3 |
| Medical Toxicology | 3 |
| Portable X-Ray Supplier (Billing Independently) | 3 |
| General Psychiatry | 3 |
| Adult Congenital Heart Disease | 2 |
| Medical Genetics and Genomics | 2 |
| Nuclear medicine | 2 |
| Mammography Screening Center | 1 |
| All other suppliers, e.g., Drug Stores | 1 |
| Oral and Maxillofacial Pathology | 1 |
| Epileptologists | 1 |