Thomas P. Mac Mahon

THOMAS P. MAC MAHON has been Chief Executive Officer of Laboratory
Corporation of America Holdings since January 1997 and Chairman since
April 28, 1996. Prior to his appointment as LabCorp’s Chief Executive
Officer in 1997, Mr. Mac Mahon 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. Mac Mahon holds a BS in Marketing from
St. Peter’s College and an MBA in Marketing from Fairleigh Dickinson
University.