Aside from appearing in television, he made his Broadway debut in the 2001 production of "The Music Man" and starred in the 2005 film "The Sisters". Following the series conclusion of "Will & Grace" in 2006, McCormack starred as the leading role in the New York production of "Some Girl(s)". He starred in the television miniseries "The Andromeda Strain" (2008) and returned to television in 2009 in the TNT drama "Trust Me", which was cancelled after one season. Also in 2009, McCormack was cast in the science-fiction movie "Alien Trespass". In addition, he starred as Dr. Daniel Pierce for three seasons of the TNT crime drama "Perception", and provided the voice of "Lucky" on The Hub's "Pound Puppies". From 2009 to 2010 he starred as Dr. Max Kershaw, the psychiatrist turned boyfriend of Julia Louis-Dreyfus' title character in "The New Adventures of Old Christine."