In order to study the factors influencing storage, access, and retrieval of idioms as they relate to advancing age, we investigated the properties of idioms that directly influence idiom production and their relation to aging. In particular, we selected measures of structural complexity (grammatical class, syntactic frozenness) and a measure of semantic complexity (compositionality) along with several other measures that interact with representation and processing (idiom familiarity, word frequency, semantic neighborhood density). The performance of younger adults (age 18–30) was predicted by idiom familiarity; that of older adults (age 60–85) was predicted by frozenness. In addition, both younger and older adults performed better on full-sentence idioms than on verb-phrase ones. The results are discussed within a theoretical framework of idiom production and aging.