A prior section 233 of Pub. L. 88–643, title II, Oct. 13, 1964, 78 Stat. 1048, related to voluntary retirement and was set out as a note under section 403 of this title prior to the general amendment of Pub. L. 88–643 by section 802 of Pub. L. 102–496.

1993—Pub. L. 103–36 designated existing provisions as subsec. (a) and added subsec. (b).

Section effective on first day of fourth month beginning after Oct. 24, 1992, see section 805 of Pub. L. 102–496, set out as a note under section 2001 of this title.