of benefits in 1989 established a "pattern” of benefit increases such that the Plan's later rescission of the 1999 Benefits Increase, which was adopted ten years after the 1989 increase, violated the anti-cutback rule. We find this argument to be without merit as a matter of law. 18 . Thornton also alleges that the Board breached its fiduciary duty by favoring one class of Plan participants over another class, specifically by eliminating the 1999 Benefits Increase for pre-February 1, 1999 retirees while maintaining it for Plan participants retiring on or after that date. Thornton waived this argument on appeal, however, by waiting until his reply brief to address the issue, rather than raising it first in his opening brief. United States v. Perkins, 994 F.2d 1184, 1191 (6th Cir.1993) (<HOLDING>). 19 . 29 U.S.C. § 1132(a) states in relevant
holding that arguments raised for the first time in a reply brief are forfeited holding that an argument raised for the first time in a reply brief is waived holding that issue raised for the first time in reply brief was waived holding issues raised for the first time in a reply brief are not properly before this court holding that issues not raised before the district court cannot be raised for the first time before this court