The attentional boost effect (ABE) refers to enhanced memory for information that is learned under conditions of divided attention in which participants encode stimuli while performing a second task involving target monitoring. The present investigation examined the ABE in young and young-old adults in forced-choice recognition (Experiment 1), and in young, young-old, and older-old adults in yes/no recognition that included manipulations of word frequency and study-to-test changes in modality (Experiments 2 and 3). Contrary to previous findings that showed an elimination of the ABE in young-old adults (Bechi Gabrelli, Spataro, Pezzuti, & Rossi-Arnaud, 2018), young-old adults exhibited an ABE whose magnitude did not differ from that of young adults. Older-old adults, however, displayed a reduced ABE compared with the young. The results may be understood by a framework in which age-related cognitive declines create vulnerable boosted memories in the ABE that are more easily disrupted over time than the boosted memories in young adults. (PsycINFO Database Record (c) 2019 APA, all rights reserved).