The purpose of this study was to investigate the validity evidence for the use of the 19-item and 20-item short forms of the MUSIC Model of Academic Motivation Inventory (College Student version) with undergraduate students. These shorter forms of the MUSIC Inventory could be beneficial to teachers and researchers. Our analysis included inventory responses from 2951 undergraduate students in 32 courses at a large public university in the Southeastern United States. Validity evidence for the scores was based on our examination of three types of validity inference: scoring, generalization, and extrapolation. We compared the short and long forms of the MUSIC Inventory using descriptive statistics, Cronbach's alpha values, Pearson's correlation coefficients, and fit indices from factor analyses. We were able to confirm all five of the validation hypotheses, thus demonstrating that the short forms of the MUSIC Inventory can provide scores that are valid for use with undergraduate students.