The half-hour pilot will also star Reno Wilson, Jolie Jenkins and Constance Zimmer.
The comedy centres on two friends who embark on very different lives. McCormack will play Dean, a heart surgeon with a baby, while Wilson is cast as Seth, a contractor with a new empty nest.
Jenkins and Zimmer will play Dean and Seth's wives respectively.
McCormack is best known for his role as Will in US sitcom Will & Grace. Last year, the actor dismissed rumours that there would be a spinoff of the show.