EXHIBIT 21 SUBSIDIARIES(1) Owned Directly by Laboratory Corporation of America Holdings: Name Jurisdiction of Organization - --------------------------------- ----------------------------- LabCorp Delaware, Inc. Delaware LabCorp, BVBA Belgium Lab Delivery Service of New York City, Inc. New York Laboratory Corporation of America Delaware Viro-Med Laboratories, Inc. Minnesota National Genetics Institute California LabCorp Limited United Kingdom Path Lab Holdings, Inc. Delaware Center for Genetic Services, Inc. Texas Clipper Holdings, Inc. Delaware Clinical Laboratories, Inc. Pennsylvania DIANON Systems, Inc. Delaware New Molecular Diagnostics Ventures LLC (2) Delaware Owned Directly by Laboratory Corporation of America: Name Jurisdiction of Organization - --------------------------------- ----------------------------- Dynacare Laboratories, Inc. Delaware Owned Directly by Path Lab Holdings, Inc.: Name Jurisdiction of Organization - --------------------------------- ----------------------------- Path Lab, Inc. New Hampshire Owned Directly by Path Lab, Inc.: Name Jurisdiction of Organization - --------------------------------- ----------------------------- Medical Management Services, Inc. Vermont Owned Directly By Medical Management Services, Inc.: Name Jurisdiction of Organization - --------------------------------- ----------------------------- Springfield Medical Laboratory, Inc. Vermont (1) All Subsidiaries are 100% owned by Laboratory Corporation of America Holdings or Subsidiaries of Laboratory Corporation of America Holdings, unless otherwise noted. Excludes legal entities with inactive business operations. (2) Laboratory Corporation of America Holdings owns 90% of New Molecular Diagnostics Ventures LLC Owned Directly by Clipper Holdings, Inc.: Name Jurisdiction of Organization - --------------------------------- ----------------------------- 3065619 Nova Scotia Company Nova Scotia Owned Directly by 3065619 Nova Scotia Company: Name Jurisdiction of Organization - --------------------------- ----------------------------- Dynacare Company Nova Scotia Owned by Dynacare Company: Name Jurisdiction of Organization - --------------------------- ----------------------------- ExecMed Health Services Inc. Ontario 896988 Ontario Inc. Ontario Dynacare Realty Inc. Ontario Dynacare Laboratories Limited Partnership (3) Ontario Dynacare G.P. Inc. Ontario Dynacare Holdco LLC Delaware Owned By Dynacare Laboratories Limited Partnership: Name Jurisdiction of Organization - --------------------------- ----------------------------- Gamma-Dynacare Medical Laboratories (4) Ontario Owned Directly by Gamma-Dynacare Medical Laboratories: Name Jurisdiction of Organization - --------------------------- ----------------------------- GDML LeaseCo, Inc. Ontario Dynacare Gamma Institutional Laboratory Services Limited Ontario Ultra-Med Developments Inc. Ontario Gamma Dynacare Leasing Corporation Ontario Dynacare X-Ray Services Limited Ontario RD Belenger & Associates Ltd. (5) Ontario Centre Diagnostique Analab, Inc. (6) Quebec (3) Dynacare Company owns 99.9% of Dynacare Laboratories Limited Partnership. Dynacare GP Inc. owns the remaining 0.1% interest. (4) Dynacare Laboratories Limited Partnership owns a 72.99% interest in Gamma-Dynacare Medical Laboratories. (5) Gamma-Dynacare Medical Laboratories owns a 70% interest in RD Belenger & Associates Ltd. (6) Gamma-Dynacare Medical Laboratories owns a 75% interest in Centre Diagnostique Analab Inc. Owned by Dynacare Laboratories Inc.: Name Jurisdiction of Organization - ------------------------------------ ---------------------------- Dynacare Northwest Inc. Washington Clinical Laboratories Cheyenne Wyoming Dynacare Southwest Laboratories, Inc. Texas LabSouth Inc. Delaware Dynacare Oklahoma, Inc. Delaware Dynacare Mississippi, Inc. Delaware HHD Genpar, Inc. Texas Dynacare Louisiana, LLC Louisiana Ownership Interests by Dynacare U.S. Subsidiaries: Name Jurisdiction of Organization - ------------------------------------ ---------------------------- HH/DL, LP (7) Texas SW/DL LP (8) Delaware UHS/DL, LP (9) Delaware (7) Dynacare Southwest Laboratories, Inc. owns a 49.5% interest, Dynacare Laboratories, Inc. owns a 49.5% interest and HHD Genpar, Inc. owns the remaining 1% interest in HH/DL, LP. (8) HH/DL, LP owns a 99% interest and HHD Genpar, Inc. owns the remaining 1% interest. (9) Dynacare Laboratory Management, Inc. holds a 94.8% and DL/UHS Inc. holds a 0.4% interest in UHS/DL, LP. Dynacare Laboratories Inc. holds a 50% interest in DL/UHS Inc.