[2] On January 25, 2023, ahead of the official Season 20 renewal, Krista Vernoff announced her departure as showrunner from Grey's and its spin-off series Station 19, however, she will still be attached to the show as an executive producer and through her company Trip the Light Productions.

[23] On November 15, 2023, the first table read for the season premiere took place, as shared by actors Camilla Luddington, Midori Francis, Adelaide Kane, Anthony Hill and James Pickens, Jr. through Instagram stories.

On May 18, 2023, hours before the premiere of the previous season finale, it was announced the return of the two remaining original castmates Chandra Wilson and James Pickens, Jr. portraying their characters Dr. Miranda Bailey and Dr. Richard Webber, respectively; as well as the return of long-time cast members Kevin McKidd, Kim Raver, Camilla Luddington and Caterina Scorsone to portray Dr. Owen Hunt, Dr. Teddy Altman, Dr. Jo Wilson and Dr. Amelia Shepherd, respectively.

Other cast members who reecured throughout the season include Debbie Allen, Jaicy Elliot, and Scott Speedman as Drs.

[citation needed] On February 10, 2024, it was announced the return of Jessica Capshaw and Alex Landi to portray their characters Dr. Arizona Robbins and Dr. Nico Kim, respectively as guest stars.