Sexting is associated with a range of negative outcomes among youth. While parents and caregivers can play a critical role in the prevention of youth risk behaviors, nationally representative research has yet to examine U.S. caregivers' perceptions of youth's sexting motivations to help inform sexting risk prevention efforts. Using 2018 and 2019 Fall ConsumerStyles online panel survey data (N = 1,034), this study estimated and examined U.S. caregivers' perceptions of youth's sexting motivations and the associations of such perceptions with concerns about their children (ages 10-17) getting and sharing sexts (sexual messages, photos, videos). Weighted percentages were calculated to describe caregivers' perceptions of youth's sexting motivations. Logistic regression analyses were performed to examine associations between caregivers' perceptions and concerns about youth's sexting. Results suggest that many caregivers perceive youth sext because they think it is harmless (72.79%), they want to be popular or boast (70.51%), they have low self-esteem (52.00%), and/or it is part of their sexual exploration process (49.05%). Fewer caregivers perceived that youth sext because they want revenge (21.80%) or to harm others (16.06%). Caregivers' concerns about their children getting and sharing sexts were related to perceiving that youth sext because of low self-esteem, sexual exploration processes, or to harm others. The perception that youth sext because they want to be popular or boast was related to concern about youth getting but not sharing sexts. Odds of concern were significantly higher among caregivers from some racial/ethnic subgroups. Findings can inform sexting prevention efforts that include caregivers.