The Trek Equinox TTX SSL has team member Ryan Baumann's name on the top tube and custom-painted Bontrager aero bars.
It was being stored in an empty room next to the Tour de France legend's store in Austin, Texas when it was taken.
Mellow Johnny's have appealed for help on their Twitter page, saying: "Help!! We had Trek-Livestrong TT bike stolen Sunday November 22, similar to one pictured. Please RT [Re-Tweet]... Stolen bike has some unique features like TT bars that were special for the team."
Earlier this year, seven-time Tour de France winner Armstrong used Twitter to help recover his time trial bike after it was stolen from the back of a van during the Tour of California.