In native speakers of gender-marking languages, mechanisms of gender production appear to be affected by the morphophonological cues to gender present in the noun phrase. This influence is manifested in higher levels of production accuracy when more transparent cues to gender are present in comparison to when they are not. The goal of the present study was to examine the role of morphophonological cues to gender in the production of gender agreement in native speakers and second language learners of Spanish in light of the Marking and Morphing account of agreement (Eberhard et al., 2005). Participants repeated and completed complex subject noun phrases with head nouns that varied in gender and gender-marking transparency. Analyses of accuracy rates along with Marking and Morphing model simulations of the results indicated that, contrary to previous findings, native speakers were not affected by gender-marking transparency. However, based on model simulations, second language (L2) learners were affected by the morphophonological form of the head noun.