SECOND AMENDMENT TO THE LABORATORY CORPORATION OF AMERICA HOLDINGS MASTER SENIOR EXECUTIVE CHANGE IN CONTROL SEVERANCE PLAN

1.

Section 5.1 of the Plan shall be amended by deleting from the beginning of the first sentence the phrase “Subject to Sections 3.2 and 3.3,” and replacing it with the phrase “Subject to Sections 3.2, 3.3 and 5.2,”; and

2.

Section 5.2 of the Plan including all prior amendments thereto is hereby deleted in its entirety and shall be replaced with the following:

Section 280G of the Code. Notwithstanding the application of the calculation of benefits hereunder, in the event that the payments or distributions to be made by the Company to or for the benefit of the Covered Employee (whether paid or payable or distributed or distributable pursuant to the terms of this Plan, under some other plan, agreement, or arrangement, or otherwise) (a “Payment”) constitute “parachute payments” within the meaning of Section 280G of the Code, then the Payment to the Covered Employee shall be reduced to $1 below the safe harbor limit (as described in Section 280G(b)(2)(A)(ii) of the Code) if said reduction in Payment would result in the Covered Employee retaining a larger amount, on an after-tax basis, taking into account the excise and income taxes imposed on the payments and benefits.

LABORATORY CORPORATION OF

AMERICA HOLDINGS

By: /S/ F. SAMUEL EBERTS III

            F. Samuel Eberts III

Title:  Senior Vice President and Chief Legal

           Officer