Stereotype threat arises when the activation of negative stereotypes about a group impairs performance of stigmatized individuals on stereotype relevant tasks. There is ample evidence that stereotype threat leads to performance detriments by consuming executive resources. Several studies indeed showed that working memory (WM) mediates stereotype threat effects among young adults. More recently, researchers have sought to understand whether the same mechanisms underlie age-based stereotype threat, but findings are mixed regarding the role of WM and some authors rather favor a motivational explanation based on regulatory fit. The present review critically appraises the empirical support for distinct forms of stereotype threat effects mediated by distinct mechanisms. We propose a novel approach based on one of the most recent WM models, the time-based resource sharing model, to evaluate the impact of stereotype threat on attentional resources in WM among both young and older adults.