Music-evoked autobiographical memories (MEAMs) are typically elicited by music that listeners have heard before. However, recent evidence indicates that even music that is unfamiliar to the listener can still cue autobiographical memory. Here we examined how perceived familiarity, music-evoked affect, and developmental timing of music release (childhood, adolescence, young adulthood) were associated with evoked memories in older adults (N=75, ages 65-80) who listened to familiar and unfamiliar music in a pre-registered study. More positive music-evoked affect was related to higher MEAM likelihood for both familiar and unfamiliar music. Higher perceived familiarity was associated with the occurrence of MEAMs in response to familiar, but not unfamiliar, music. We also replicated “reminiscence bump” effects for familiar music such that participants reported more MEAMs in response to music released during their adolescence (14-18) than young adulthood (20-25); however, our results indicate that this bump may begin earlier (i.e., middle childhood). Together, our results suggest different mechanisms underlying MEAMs for familiar and unfamiliar music: music-evoked affect may facilitate MEAMs regardless of previous exposure, but perceived familiarity supports MEAMs only for familiar music.