45 C.F.R. § 86.56
(b) Prohibitions. A recipient shall not:
(3) Administer, operate, offer, or participate in a pension or retirement plan which establishes different optional or compulsory retirement ages based on sex or which otherwise discriminates in benefits on the basis of sex.
(Secs. 901, 902, Education Amendments of 1972, 86 Stat. 373, 374; 20 U.S.C. 1681, 1682)