Hansen continued to make music, recording as a guest and session singer for many projects, including Slash's Snakepit, Fergie Fredriksen, Don Dokken, and Bourgeois Pigs.

In 1998 Hansen joined the band Unruly Child, replacing vocalist Mark Free.

In 2003, Hansen joined forces with Fabrizio V.Zee Grossi and recorded a self-titled album under the band name Perfect World.

Hansen joined Foreigner in 2005, after Lou Gramm left in 2003 due to continuing conflicts with Mick Jones.

Hansen divides his time between two homes in Los Angeles – one in Calabasas and the other in Malibu.