[4] As such, drastic creative changes occurred in the season, with Vernoff retiring Martin Henderson, Jessica Capshaw, and Sarah Drew's characters.

[7] On April 20, 2018, ABC officially renewed Grey's Anatomy for a network primetime drama record-tying fifteenth season.

[10] As Owen helps Megan make the trip to California where she will start her new life with Nathan and her son, Farouk, they reminisce on their time spent in Fallujah, Iraq.

[38][39] Hinton had previously been in talks of leaving the show at the end of the 12th season when she was cast in the Shondaland comedy pilot Toast, but ABC passed on the project.

[42] In August 2017, it was announced that Abigail Spencer would replace Bridget Regan as Megan Hunt for a multi-episode arc this season.

[43] After recurring in the previous season as the controversial character, Eliza Minnick, it was announced in August 2017 that Marika Dominczyk would not return to the show.

[44] On September 13, 2017, another guest-star was announced in Greg Germann (Ally McBeal), and later it was revealed that his character would be Tom Koracick, Amelia's neurosurgery mentor.

[45] On October 9, 2017, the new group of interns to join the cast in the fourth episode "Ain't That A Kick In The Head" was announced to include Jeanine Mason (So You Think You Can Dance) as Sam Bello, Alex Blue Davis as Casey Parker, Rushi Kota as Vik Roy, Jaicy Elliot as Taryn Helm, Sophia Ali as Dahlia Qadri, and Jake Borelli as Levi Schmitt.

[47] On January 31, 2018, it was announced that Candis Cayne would be joining the show as Dr. Michelle Velez for a multi-episode arc revolving around a transgender character receiving a ground-breaking surgery.

[49] On April 20, 2018, it was released that Geena Davis would return for the episode "Cold as Ice" as Dr. Herman to present a new opportunity for Arizona.