When does emily come back in criminal minds?
No context provided
When does emily first come back as a special guest in criminal minds?
season 9 "200" season 9 episode 14
According to Matthew Gray Gubler, he will be directing an episode in which another BAU member will be leaving the cast this season, that member being Derek Morgan (Shemar Moore). Shemar Moore left the show as Derek Morgan, which aired on March 23, 2016. On February 10, 2016, it was announced that Paget Brewster would return as Emily Prentiss for one episode later in season 11 episode 19, titled "Tribute". The season ended on May 4, 2016, with the show's first cliffhanger finale since the fifth season. Messer said she felt it was time for another cliffhanger and thought that it served as a "really fun launch pad" into the twelfth season, which was officially ordered two days later.
When does emily come back as a special guest star during season 11 in criminal minds?
"Tribute" season 11 episode 19
Criminal Minds (season 11)
No context provided
What season does emily come back as a regular character in criminal minds?
12 season 12
Criminal Minds (season 9)
https://en.wikipedia.org/wiki/Criminal%20Minds%20%28season%209%29
Criminal Minds (season 7)
https://en.wikipedia.org/wiki/Criminal%20Minds%20%28season%207%29
Criminal Minds (season 11)
https://en.wikipedia.org/wiki/Criminal%20Minds%20%28season%2011%29
Criminal Minds (season 12)
https://en.wikipedia.org/wiki/Criminal%20Minds%20%28season%2012%29
Brewster returned for guest appearances in the season 9 episode "200" in 2014 and the season 11 episode "Tribute" in early 2016 before returning as a regular cast member in the season 12 episode "Taboo" later in the year.
Emily Prentiss
Prentiss first appeared in "The Last Word" (episode nine of season two), replacing Agent Elle Greenaway (Lola Glaudini), who had quit in "The Boogeyman". Her role in the show's sixth season was reduced, for what Brewster believed to be financial reasons. Brewster returned to her role for the show's seventh season. Her final episode as a main cast member was the May 16, 2012 episode "Run." 
Emily Prentiss
The list contains the main cast of Criminal Minds season 12: Paget Brewster as Supervisory Special Agent Emily Prentiss (BAU Unit Chief & Co-Communications Liaison) (Ep. 3 forward).
The Criminal Minds character Supervisory Special Agent Emily Prentiss, played by Paget Brewster, made her first appearance in the show's second season and left the main cast in the season 7 episode "Run". Prentiss returned as a special guest in the season 9 episode "200" and the season 11 episode "Tribute", before rejoining the main cast in the season 12 episode "Taboo".