Thomas P. MacMahon

THOMAS P. MacMAHON has been Chief Executive Officer of Laboratory
Corporation of America Holdings since January 1997 and Chairman since
April 28, 1996. He has had a long and diverse association with
businesses in clinical laboratory testing and diagnostic technology and
played a pioneering role in commercializing the use of polymerase chain
reaction (PCR) technology. Prior to his appointment as LabCorp’s Chief
Executive Officer in 1997, Mr. MacMahon was Senior Vice President of
Hoffmann-La Roche Inc. from 1993 to January 1997 and President of Roche
Diagnostics Group and a member of the Executive Committee of Hoffmann-La
Roche from 1988 to December 1996. At Hoffmann-La Roche he had been
responsible since 1988 for the management of all United States
operations of the diagnostic business. As a member of the Executive
Committee of Hoffmann-La Roche Inc., his responsibilities included
oversight of Roche Biomedical Laboratories (one of LabCorp’s predecessor
companies), then a subsidiary of HLR Holdings Inc., from 1988 to 1995.
Hoffmann-La Roche, Roche Diagnostics Group, and HLR Holdings Inc. are
indirect, wholly owned subsidiaries of Roche Holdings Ltd, an
international healthcare concern based in Basel, Switzerland. Mr.
MacMahon holds a BS in Marketing from St. Peter’s College and an MBA in
Marketing from Fairleigh Dickinson University.