Identity crimes pose serious risks and challenges for youth in foster care. As young people move through various out-of-home placements and schools, their personal data are often widely disseminated, difficult to secure, and thus vulnerable to theft and misuse. When they transition from foster care to adulthood, identity crime victims with compromised credit histories may be denied loans, employment, and/or housing during the already-precarious period of emerging adulthood. Even though federal law requires state child welfare agencies to conduct annual credit checks for adolescent youth in foster care, little is known about the factors contributing to risk of identity crime victimization among foster care-involved youth, either before or after their initial entry into care. To address this knowledge gap, we analyze linked child welfare and consumer credit records for a population-based cohort of 4,670 youth (age 14 to 17) in foster care in a southeastern state who received credit checks from November 2015 through December 2021.Using gradient boosted machine learning, we find that prior identity crime victimization before the youth first entered care is the strongest predictor of victimization while in foster care.Implications of these findings for policy and practice are discussed.