Educational stakeholders have long known that students might not be fully engaged when taking an achievement test and that such disengagement could undermine the inferences drawn from observed scores. Thanks to the growing prevalence of computer-based tests and the new forms of metadata they produce, researchers have developed and validated procedures for using item response times to identify responses to items that are likely disengaged. In this study, we examine the impact of two techniques to account for test disengagement--(a) removing unengaged test takers from the sample and (b) adjusting test scores to remove rapidly guessed items--on estimates of school contributions to student growth, achievement gaps, and summer learning loss. Our results indicate that removing disengaged examinees from the sample will likely induce bias in the estimates, although as a whole accounting for disengagement had minimal impact on the metrics we examined. Last, we provide guidance for policy makers and evaluators on how to account for disengagement in their own work and consider the promise and limitations of using achievement test metadata for related purposes.