(a) The Secretary of Defense may pay the expenses referred to in section 5742(b) of title 5 in the case of any employee of the National Security Agency who dies while on a rotational tour of duty within the United States or while in transit to or from such tour of duty. (b) For the purposes of this section, the term “ rotational tour of duty ”, with respect to an employee, means a permanent change of station involving the transfer of the employee from the National Security Agency headquarters to another post of duty for a fixed period established by regulation to be followed at the end of such period by a permanent change of station involving a transfer of the employee back to such headquarters. ( Pub. L. 86–36, § 18 , formerly § 17, as added Pub. L. 102–183, title IV, § 405 , Dec. 4, 1991 , 105 Stat. 1267 ; renumbered § 18, Pub. L. 102–496, title III, § 304(a) , Oct. 24, 1992 , 106 Stat. 3183 .) Editorial Notes Codification Section was formerly classified in a note under section 402 of this title prior to editorial reclassification as this section.