The Spanish subjunctive has been the focus of much SLA research, largely because it poses difficulties for learners of Spanish whose L1 is English (e.g., Collentine, 1993; Stokes & Krashen, 1990; Terrell et al., 1987). Investigating the same feature in heritage learners of Spanish can provide more information about their linguistic development and also has the potential to inform our knowledge of the acquisition of the subjunctive in traditional FL learners. The present study investigates whether heritage learners recognize grammatical and ungrammatical modal choice in volitional constructions. These constructions have been selected because this use of the subjunctive does not vary by a speaker's dialect or by belief about the idea being expressed. Furthermore, given that theories of language attrition posit that the structures that are acquired earliest are the last to be lost (e.g., De Bot & Weltens, 1991) and that Spanish monolingual children acquire the subjunctive in volitional constructions first (Blake, 1980; 1983), heritage learners who have experienced some language attrition may still have knowledge of this feature. To investigate the effect that language attrition or incomplete acquisition may have on this knowledge, I also compared the SHL learners in the sample who were early bilinguals in English (those born in the United States or who immigrated before age 6) with those who were late bilingual (those who immigrated between ages 6 and 13). Students enrolled in Spanish for Heritage Learners (SHL) and Spanish as a Foreign Language (SFL) courses at three universities in the Northeast completed grammaticality judgment (GJ) and editing tasks, which contained examples of correct and incorrect mood choices, as well as distracter items. The GJ task also required participants to explain their judgments. The results indicate that SHL learners outperform their SFL peers on recognizing correct mood selection. No significant differences were found between early and late bilinguals. SHL and SFL learners tended to correct utterances that they had rejected of judged neutrally but gave different types of reasons for accepting utterances. There were several similarities between early and late bilinguals in terms of their reasons for their judgments of utterances.