McCourt was in the original Broadway cast of Wicked in 2003, playing the minor roles of Elphaba's father and the Ozian official, and understudying the principal parts of the Wizard (filling in for Joel Grey for two weeks in 2004) and Doctor Dillamond (assuming the role for eight months, 2005-2006). He returned to Wicked off and on as late as 2013. McCourt had similar ensemble/understudy duties in Titanic (also playing the cello/double bass on-stage as a member of the ship's orchestra), the original cast of Mary Poppins (as Von Hussler and understudying Mr. Banks), and Women on the Verge of a Nervous Breakdown (with Brian Stokes Mitchell). Off-Broadway work includes Bat Boy: The Musical (as Dr. Parker, with Kerry Butler).