The single-camera project is described as "a heartwarming comedy about a blended family of a gay couple, Bryan (Rannells) and David (Bartha), and the woman who becomes a surrogate (King) to help them start a family." Barkin is cast as the surrogate's glamorous grandmother.
Rannells' previous Broadway outings include leading roles in Jersey Boys and Hairspray.
As previously reported, NBC has ordered 13 episodes of the new comedy "Go On," which stars Tony Award winner Laura Benanti, Matthew Perry ("Friends"), Tony winner Julie White (The Little Dog Laughed), Khary Payton, Allison Miller and Suzy Nakamura.
The network has also picked up "1600 Penn," a White House family comedy starring Mormon's Josh Gad, Bill Pullman and "Hairspray" actress Brittany Snow; "Save Me," starring Anne Heche; "Animal Practice," with Justin Kirk; and "Revolution."