Younger adults use both semantic and phonological cues to quickly localize the referent during sentence comprehension. ERP studies have shown that older adults, as a group, are less apt at using contextual semantic cues to predict upcoming words. The current study extends the investigation of contextual cue processing beyond semantic cues, by comparing younger and older adults in their ability to use phonological cues in indefinite articles (a/an) in an eye-tracking paradigm. Our results suggest that both age groups use such contextual phonological information, but with different timelines: younger adults use the cues to anticipate an upcoming word, whereas older adults show delayed cue processing after the target word has been spoken. Together with past research, these findings support a model of sentence comprehension in which the use of contextual cues continues with aging, but is no longer as efficient as in the young system for anticipatory word retrieval.