According to the constructive episodic simulation hypothesis (Schacter & Addis, 2007), both remembered past and imagined future events rely heavily on episodic memory. An alternative hypothesis is that observed similarities between remembering and imagining reflect the influence of broader factors such as descriptive ability, narrative style, or inhibitory control. We attempted to distinguish between these 2 hypotheses by examining the impact of an episodic specificity induction on memory, imagination, and picture description in young and older adults. In Experiment 1, participants received the specificity induction or a control induction prior to the memory, imagination, and description tasks. Older adults provided fewer internal (i.e., episodic) and more external (i.e., semantic) details than young adults across the 3 tasks irrespective of induction. Critically, however, the specificity induction selectively increased internal but not external details for memory and imagination in both age groups compared with the control induction. By contrast, the induction did not affect internal (or external) details for picture description. Experiment 2 replicated these results in young adults using a different control induction. Our findings point to a dissociation between episodic processes involved in memory and imagination and nonepisodic processes involved in picture description.