Noncognitive characteristics are gaining importance in addressing the persistent challenges facing youth in diverse settings. Measurement invariance of two youth developmental assets, Support and Positive Identity, is evaluated across grade levels and English language learner (ELL) subgroups of Latino students in 6th through 12th grade. Explanatory item response modeling is used to evaluate measurement invariance. The measurement of Latino students' sense of support and positive identity varies depending on their developmental stage and language status. Students at later grade levels tend to require higher levels of Support to endorse items in the Support measure. There is a nonlinear relation between students' grade level and item functioning for Positive Identity; students' transition from middle to high school may influence the way they respond to Positive Identity items. This has implications for the measurement of assets with diverse Latino youth and for Latino youth development.