The actor, who played Edie Britt's (Nicollette Sheridan) troubled husband Dave Williams in the ABC show, will appear as a senator in CSI's upcoming ninth season.
His character Gordon Hamilton, described by TVLine as the "ultimate politician", will be injured along with Lindsay Monroe (Anna Belknap) in a shooting during his campaign rally.
McDonough's episode is believed to be the fourth of the CBS police procedural's ninth run.
The Captain America and Justified star recently filmed scenes for Frank Darabont's TNT drama LA Noir.
He has also been tipped for a role in RED 2 alongside Bruce Willis, John Malkovich, Mary-Louise Parker, Helen Mirren and Catherine Zeta-Jones.
CSI: NY returns to CBS on September 28 at 8/7c.