Mark Duplass also joins the Mad Men and CSI stars in the project from first-time director Charlie McDowell, reports Deadline.
Moss and Duplass will play a young couple who are dealing with marital issues, while Danson will play their therapist.
Justin Lader has written the script, while Mel Eslyn will produce. Duplass will serve as an executive producer.
McDowell is also known as the person behind a popular Twitter feed featuring a man thinking like women after he discovers he can overhear conversations from his female neighbours in the apartment above him.
The writer turned the feed into an upcoming book titled Dear Girls Above Me.
Elisabeth Moss recently said that she is "very emotional" about the upcoming end of AMC series Mad Men.