Menzel will appear in just a handful of stops on the tour, including the Segerstrom Center for the Arts in Costa Mesa, where the tour will play for about a week in January, as well as in San Diego.
She is scheduled to kick off the tour in Denver starting Oct. 13 at the Buell Theatre.
"If/Then," which features songs by Brian Yorkey and Tom Kitt, opened on Broadway in 2014 and ran for nearly a year at the Richard Rodgers Theatre. The musical received mixed reviews, but Menzel was singled out for praise for her performance as a woman who explores alternate destinies.
The show is scheduled to run at the Pantages from Dec. 8 to Jan. 3. It will run at the Segerstrom from Jan. 19 to 24.
Menzel provided the voice of Elsa in the hit Disney animated movie
At this year's Oscars, Menzel returned the favor by introducing Travolta as "Glom Gazingo."