The current study contributes to the argument regarding whether L2 learners up to advanced levels make agreement errors on grammatical gender. It reports gender agreement accuracy on a written Grammaticality Judgment Task (GJT) and an Elicited Oral Production Task (PDT) on known nouns assigned the correct gender by participants on a vocabulary test. Participants were 15 intermediate and 15 advanced second language Spanish learners (first language English), and 15 native Spanish speakers. Overall results found that intermediate learner agreement scores differed significantly from those of native speakers on the GJT and PDT, but advanced learner scores did not differ from those of native Spanish speakers on either task. Findings for advanced learners demonstrate that once these learners know the meaning of a noun and can correctly assign its gender, gender agreement is relatively unproblematic. Results of the present study reinforce the importance of focusing learner attention on gender assignment while teaching noun meanings at least through intermediate levels, to aid in gender agreement accuracy by strengthening co-occurrence relations between nouns and their modifiers. Findings are discussed in terms of the lexical gender learning hypothesis (Grüter et al. 2012), which focuses on the relationship of input and experience to gender acquisition.