In an effort to articulate an agenda for learner outcomes research linked to the Standards for Foreign Language Learning in the 21st Century, this review examines the profession's current conceptualization of the National Standards in research on learner outcomes across various levels of instruction. The research literature reviewed reveals that, to date, empirical studies of learner outcomes have been conducted only on the Communication goal of the National Standards. Consequently, in the majority of the studies reviewed in the other goal areas have not conceptualized learner outcomes from a National Standards perspective, nor have they defined outcomes in the ways they are presented in the National Standards. Recommendations for future research are provided, which include the creation of design-based research communities and partnerships in K–16 foreign language education. A primary goal for this research agenda is to expand the scope of the current research by (1) exploring the National Standards that have yet to be investigated in the research, (2) designing and investigating innovations related to those National Standards, and ultimately (3) deepening the understanding of learner processes, development, and outcomes related to the National Standards.