This is the 350th episode of the series.
This is the first episode since season five's Control (2003) to feature Dick Wolf as a credited writer.
This was part two of a two-night, three episode crossover with Chicago Fire (2012) (Nobody Touches Anything (2014)) and Chicago P.D. (2014) (They'll Have to Go Through Me (2014)).
When Benson tells Voight she had a partner that used to work the way Voight does, she is (of course) referencing Elliot Stabler but not by name. The last time Stabler was referenced was in Surrender Benson (2013), when Benson was held captive by William Lewis.
At the beginning of the episode, Amaro asks Fin if Jay Halstead was the detective that hit on Rollins in Chicago, to which Fin replies "Nah. Some other pretty boy." They are referring to the events of the Chicago P.D. (2014) episode Conventions (2014), in which Fin and Rollins went to assist Chicago Police Department and the detective in question was Adam Ruzek. Coincidentally, Amaro and Ruzek would be partnered up in the Chicago P.D. episode in this crossover.