10 U.S.C. § 8102
Regular Navy: retired flag officers on active duty
Except in time of war or national emergency, not more than ten retired flag officers of the Regular Navy may be on active duty.
( Aug. 10, 1956, ch. 1041 , 70A Stat. 312 , § 5450; Pub. L. 96–513, title V, § 503(21) , Dec. 12, 1980 , 94 Stat. 2912 ; renumbered § 8102, Pub. L. 115–232, div. A, title VIII, § 807(b)(1) , Aug. 13, 2018 , 132 Stat. 1834 .)