She won the 2018 Tony Award for Best Featured Actress in a Musical for her performance as Carrie Pipperidge in a Broadway revival of Carousel.

Her other credits on Broadway include Elphaba in Wicked (performing during the production's tenth anniversary), Godspell, and Jan in Grease.

[7] From September 2019 to November 2023, Mendez co-starred on the CBS drama series All Rise as court stenographer Sara Castillo.

[11] In 2012, Mendez appeared opposite Derek Klena in the off-Broadway musical Dogfight as Eddie and Rose, and from May 2013 in Wicked as Fiyero and Elphaba respectively.

[19][20] In early 2016 she was set to star in the Broadway premiere of the musical Nerds alongside Rory O'Malley, Patti Murin and others.

[24] In the 2022 she played Mary Flynn in the off-Broadway revival of Merrily We Roll Along at New York Theater Workshop alongside Daniel Radcliffe and Jonathan Groff as well as former Wicked co-star Katie Rose Clarke.