'Masters of Sex' Adds Niecy Nash, 'Nurse Jackie's' Betty Gilpin for Season 4

The Hollywood Reporter Hosts the 24th Annual Women In Entertainment Breakfast - Niecy Nash - H 2015
Frazer Harrison/Getty Images for The Hollywood Reporter)

Actress Niecy Nash attends the 24th annual Women in Entertainment Breakfast hosted by The Hollywood Reporter at Milk Studios on December 9, 2015 in Los Angeles, California.  

Masters of Sex is adding some new faces for season four.

Niecy Nash and Betty Gilpin are both set to recur on the upcoming season of the Showtime drama, it was announced Thursday.

The Emmy-nominated Nash will play Louise Bell, a local Alcoholics Anonymous chairwoman running Masters' (Michael Sheen) court-ordered daily meetings. She fervently believes in AA's message and uses it to push Masters to reevaluate his life. 

Gilpin, most recently seen on Showtime's Nurse Jackie, will portray Nancy, a former medical student of Barton's (Beau Bridges) who partners with Masters, adding a second MD to the practice. Production recently began on the fourth season of the period drama ahead of its Sept. 11 season premiere.

Also starring Lizzy CaplanCaitlin FitzGerald and Annaleigh Ashford, the new season takes place in 1968 and transports viewers into the swinging 70s as the main characters engage with new partners, personally and professionally. 

Michelle Ashford, Sarah Timberman, Carl Beverly, Amy Lippman and Judith Verno exec produce the series, which hails from Sony Pictures Television.

Following her Emmy nomination for HBO's Getting On, which recently ended its three-year run, Nash has been busy with roles on Scream Queens, Brooklyn Nine-Nine and The Soul Man among others. She recently signed on for Claws, TNT's hourlong dramedy pilot about a Florida nail salon.

Gilpin is also known for her recurring role on Elementary.

Masters of Sex returns Sunday, Sept. 11 at 10 p.m. on Showtime.