The tour launched last September and the new dates will keep Paisley and Underwood on the road well into December.

They’ll hit arenas starting September 22 in Birmingham, Ala., focusing on the South and Midwest. The 26-date leg will finish up December 8 at the Allstate Arena near Chicago.

Paisley released Time Well Wasted, his fourth album, shortly before launching the tour last year.

“American Idol” winner Underwood went triple platinum with her debut album, Some Hearts, released last fall. She opened for Kenny Chesney this past June on her first major tour.