IntroductionParenting programs are widely used to prevent and ameliorate children’s emotional and behavioral problems but low levels of engagement undermine intervention effectiveness and reach within and beyond research settings. Technology can provide flexible and cost-effective alternate service-delivery formats for parenting programs, and studies are needed to assess the extent to which parents are willing to engage with digitally assisted formats. MethodsAfter Deployment, Adaptive Parenting Tools (ADAPT) is an evidence-based parenting program for military families. In the current comparative effectiveness trial, families were randomly assigned to either an in-person group (n = 95), self-directed online (n = 78), or individual telehealth (n = 71) formats of ADAPT. We explored whether children’s initial problem severity, parenting efficacy, parental depression, household income, child age, child gender, parental deployment length, and waiting time were related to parental engagement across different delivery formats. Zero-inflated Poisson regressions were used due to the distribution of the number of attended sessions. ResultsCompared to the in-person group format, parents in the individual telehealth and self-directed online formats had higher engagement levels. For the in-person format, parents who perceived their children as having more severe problems were more likely to enroll and families with a father deployed for longer time attended fewer sessions. In the self-directed online format, families with less depressed fathers were more likely to enroll. No predictors were found for the telehealth format. For all three formats, once parents took the first step to engage, they were likely to finish all sessions. DiscussionTechnology-assisted delivery formats have the potential to improve program engagement. Results from this study will help facilitate the development of specific strategies to promote engagement in the future.