The purpose of this study was to examine the predictive validity of the 2013 Oregon Kindergarten Assessment (OKA) early literacy and early math scores on 2016-2017 third-grade Smarter Balanced Assessment (SBAC) English language arts/literacy and math scores in a semi-urban school district in Oregon. The 3,200 participants were fourth-grade students in the 2017-2018 school year; this cohort of students were kindergarteners when the OKA was first administered during the 2013-14 academic year and third-graders during the 2016-2017 academic year. This was the first cohort of students to be assessed using both the OKA and the SBAC. This study used a multiple linear regression model to examine the relationship between OKA scores and third-grade SBAC scores. In addition, this study used a hierarchical regression model to examine the extent to which OKA scores interacted with students' ethnicity, socioeconomic status (SES), English learner (EL) status, classification for special education services, and gender to predict their third-grade SBAC achievement scores. The findings of this study suggest that OKA early literacy and early math scores predicted third-grade SBAC ELA and math achievement to a modest extent. The hierarchical regressions indicated that, even when interacting with demographic variables, OKA scores were only a modest predictor of third-grade SBAC outcomes. Findings from the hierarchical regressions demonstrated that models that only utilize the demographic variables of ethnicity, SES, EL status, classification for special education services, and gender have a stronger relationship with SBAC ELA and math scores than models that only utilize OKA early literacy or early math scores. (author abstract)