The Federal Government shall not be liable for any claim based upon the exercise or performance of or the failure to exercise or perform a discretionary function or duty on the part of a Federal agency or an employee of the Federal Government in carrying out the provisions of this chapter.

(Pub. L. 93–288, title III, § 305, formerly § 308, May 22, 1974, 88 Stat. 149; renumbered § 305, Pub. L. 100–707, title I, § 105(d), Nov. 23, 1988, 102 Stat. 4691.)