SAMPL9 data collection concluded around August 20, 2021 for the WP6 challenge, and November 11, 2021 for the Cyclodextrins and Phenothiazines challenge. The submission deadlines were set for November 15, 2021 (pushed back from a deadline of October 30, 2021) and February 23, 2022, respectively. The WP6-G4 guest was made optional (updated around November 8, 2021) since it contained silicon and may introduce modeling difficulties with some software. All challenge deadlines were posted in the relevant SAMPL9 host-guest challenge repository.