| University of Pittsburgh Physicians | Pittsburgh | 4,236 |
| University of Penn - Medical Group | Philadelphia | 3,505 |
| Geisinger Clinic | Danville | 3,467 |
| Phoenix Rehabilitation and Health Services Inc | Cranberry Twp | 2,800 |
| Lehigh Valley Physician Group | Allentown | 2,542 |
| Wellspan Medical Group | Ephrata | 2,480 |
| Allegheny Clinic | Pittsburgh | 2,389 |
| St Lukes Physician Group Inc | Quakertown | 2,198 |
| The Milton S Hershey Medical Center Physicians Group | Hershey | 1,623 |
| Jefferson University Physicians | Philadelphia | 1,531 |
| Temple Faculty Practice Plan Inc | Philadelphia | 1,368 |
| Fox Rehabilitation Services Inc | Wexford | 1,198 |
| Main Line Healthcare | Wynewood | 1,184 |
| Pinnacle Health Medical Services | Harrisburg | 1,019 |
| Guthrie Medical Group PC | Sayre | 795 |
| Einstein Practice Plan Inc | Elkins Park | 794 |
| Keystone Rehabilitation Systems Inc | Seven Fields | 776 |
| Upmc Community Medicine Inc | West View | 736 |
| Penn State Health Medical Group LLC | Camp Hill | 734 |
| Susquehanna Physician Services | Williamsport | 612 |
| Clinical Care Associates of the University of Pennsylvania Health. | Philadelphia | 598 |
| Nuvance Health Medical Practice PC | Reading | 595 |
| Valley Physician Services PC | Reading | 592 |
| Lancaster General Medical Group | Oxford | 586 |
| Tower Health Medical Group | West Reading | 584 |
| Regional Health Services Inc | Erie | 568 |
| Lancaster General Hospital | Lancaster | 520 |
| Novacare Outpatient Rehabilitation East, Inc. | Collegeville | 503 |
| Excela Health Physician Practices, Inc | Latrobe | 481 |
| Aria Health Physician Services | Philadelphia | 450 |
| Ati Holdings, LLC | Jenkintown | 443 |
| United Anesthesia Services PC | Wynewood | 442 |
| Abington Memorial Hospital | Abington | 442 |
| Progress Physical Therapy LLC | Philadelphia | 430 |
| Geisinger-Hm Joint Venture LLC | Montoursville | 422 |
| Dubois Regional Medical Center | Du Bois | 416 |
| Methodist Associates in Healthcare, Inc | Bala Cynwyd | 390 |
| Mount Nittany Medical Center Health Services Inc | State College | 367 |
| Family Practice Center PC | Newport | 361 |
| Butler Medical Providers | Butler | 360 |
| Trinity Health Mid-Atlantic Medical Group | Langhorne | 334 |
| Fayette Physician Network Inc | Uniontown | 320 |
| St Vincent Medical Education and Research Institute Inc | Albion | 298 |
| Dlp Conemaugh Physician Practices LLC | Johnstown | 293 |
| Ucmg LLC | Uniontown | 288 |
| Delaware County Professional Services, Inc | King Of Prussia | 287 |
| Anesthesia Specialists of Bethlehem PC | Allentown | 281 |
| Reconstructive Orthopaedic Associates II LLC | Chalfont | 281 |
| Gslpg, Inc | Orwigsburg | 277 |
| North American Partners in Anesthesia, Pennsylvania , LLC | Erie | 274 |
| Vantage Physical Therapy and Rehabilitation Inc | Johnstown | 260 |
| Upmc Pinnacle Anesthesia Services LLC | Harrisburg | 254 |
| Evangelical Medical Services Organization | Lewisburg | 248 |
| Regional Gastroenterology Associates of Lancaster, Ltd. | Lancaster | 244 |
| Heritage Valley Multispecialty Group Inc | Beaver | 227 |
| Einstein Community Health Associates Inc | Philadelphia | 224 |
| Childrens Health Care Associates Inc | Philadelphia | 220 |
| Premier Orthopaedic and Sports Medicine Associates, Ltd | Broomall | 216 |
| Drayer Physical Therapy Institute LLC | Carlisle | 214 |
| Society Hill Anesthesia Consultants PC | Philadelphia | 212 |
| St Clair Medical Services Inc | Pittsburgh | 209 |
| Oncology Hematology Association Inc | Pittsburgh | 202 |
| St Joseph Medical Group | Reading | 189 |
| Upmc Altoona Regional Health Services, Inc. | Altoona | 187 |
| Reading Hospital | Wyomissing | 186 |
| Hr Physician Services | Meadowbrook | 185 |
| Mrs Physical Therapy | Erie | 182 |
| Via Affiliates | Doylestown | 180 |
| Christiana Care Pennsylvania Inc | Glen Mills | 177 |
| Pinnacle Health Hospitalist Services LLC | Harrisburg | 177 |
| Clinical Specialty Associates | Doylestown | 171 |
| Maryland Sportscare and Rehab LLC | Littlestown | 168 |
| H2 Rehabilitation Extension Services LLC | Boyertown | 163 |
| New Directions Mental Health, PC | Mc Murray | 161 |
| Trustees of the University of Pennsylvania | Philadelphia | 157 |
| Temple Physicians Inc | Philadelphia | 156 |
| Indiana Healthcare Physician Services Inc | Punxsutawney | 154 |
| Pinnacle Health Regional Physicians | Boiling Springs | 154 |
| Cardiology Consultants of Philadelphia PC | Philadelphia | 153 |
| Allegheny Clinic Radiology | Pittsburgh | 152 |
| Apogee Medical Group of Pennsylvania PC | Erie | 151 |
| The Centers for Advanced Urology LLP | West Chester | 145 |
| Meadville Medical Center | Meadville | 143 |
| Bryn Mawr Medical Specialists Association | Bryn Mawr | 134 |
| Phoenixville Clinic Company LLC | Phoenixville | 134 |
| Ennoble Hc Nj PC | Philadelphia | 133 |
| Patient First Pennsylvania Medical Group PLLC | Mechanicsburg | 130 |
| Rgal Anesthesia Services LLC | Lancaster | 129 |
| Oss Orthopaedic Hospital LLC | York | 128 |
| Upmc Altoona | Pittsburg | 127 |
| Pivot Physical Therapy of Pennsylvania LLC | Butler | 124 |
| Optum Behavioral Care of Connecticut PC | North Wales | 123 |
| Psychogeriatric Services LLC | Lancaster | 121 |
| Valley Health Partners Community Health Center | Allentown | 120 |
| Silver Willow Wellness PC | Plymouth Meeting | 120 |
| Myeyedr Optometry of Pennsylvania LLC | Lancaster | 119 |
| Osh - PA Physicians Group, PC | Wyncote | 118 |
| Pinnacle Health Cardiovascular Institute Inc | Mechanicsburg | 117 |
| Eastern Pennsylvania Physician Alliance, LLC | Philadelphia | 114 |
| Medical Imaging of Lehigh Valley PC | Allentown | 113 |