McGerr was a guest performer on Tegan and Sara's album "The Con", released in July 2007, and can be seen recording in studio with them on the DVD entitled "The Con DVD" by Tegan and Sara. He also played drums for their next album, "Sainthood", released in October 2009. McGerr played drums on half of the tracks on Matt Nathanson's 2007 album, "Some Mad Hope", and was a guest drummer on Nathanson's 2009 album, "Modern Love". McGerr also performed drums on three songs for his Death Cab for Cutie bandmate Chris Walla's debut solo album, "Field Manual", released in 2008.