Structured Intervention Units (SIUs) were incorporated into the Correctional Service of Canada (CSC) on November 30th, 2019. Such units are intended to provide intervention-focused accommodations to offenders who cannot be safely managed in the mainstream offender population. As part of a quarterly series highlighting trends in SIUs, the current analysis examines SIU stay-level data drawn from CSC’s data warehouse for the second quarter of 2023 to 2024 (i.e., July 1st, 2023 to September 30th, 2023).