“Grey’s Anatomy” has tapped June Squibb and Hal Holbrook as guest stars, Variety has learned exclusively.

The duo will appear in the episode on Mar. 23, playing Elsie Clatch and Lewis Clatch, a married couple who visit Grey Sloan Memorial Hospital. No other details on their storyline have been revealed.

Additionally, the Mar. 23 episode will also welcome back guest star LaTanya Richardson Jackson, who will reprise her role as Maggie’s (Kelly McCreary) mother, Diane Pierce.

Squibb, who was nominated for the Academy Award for “Nebraska,” recently had an arc on Showtime’s “Shameless.” She will be in the upcoming film “Table 19.” She is repped by BRS/Gage.

Holbrook, star of his iconic Tony-winning one-man show “Mark Twain Tonight,” has been keeping busy in recent years. The multiple-time Emmy-winner had a recurring role on “Sons of Anarchy” and guest starred in an episode of “Bones” this year. He is repped by JR Talent Group.

“Grey’s Anatomy,” which was recently renewed for a fourteenth season, airs Thursday nights at 8 p.m. on ABC.