Existing research on the risks of having sex at a young age with an older partner has focused on poorer reproductive health outcomes in the adolescent years, but scant attention has been paid to the longer-term implications of these relationships. Using survey data from high school students, this "Fact Sheet" presents findings from recent Child Trends research examining whether having sexual intercourse before age 16 with a partner at least three years older was associated with becoming a teen or unmarried parent or acquiring a sexually transmitted disease (STD) by young adulthood (post-high school through the early twenties). Overall, the findings highlight the need for parents and programs to address and promote healthy sexual behaviors not only among young teens, but also among older teens and young adults. (Contains 2 figures.) [This "Fact Sheet" is based on "Older Sexual Partners During Adolescence: Links to Reproductive Out-comes in Young Adulthood," an article published in the March 2008 issue of Perspectives on Sexual and Reproductive Health.]