Are suicidal thoughts atypical during development? Does the age trajectory of suicidal thoughts parallel that of suicidal actions? Do factors that moderate the risk of suicidal actions also moderate the risk of suicidal thoughts, and does their influence vary by developmental stage? Based on life history data from 364 college students, results indicate that suicidal thoughts in childhood are typical and that the risk of such thoughts begins to increase by age nine. Risk rates are affected by demographic factors (gender, race) and by the experience of parental absence. However, the influence of these factors depends on developmental stage, with whites being at increased risk only during adolescence, and parental absence having its strongest effect during preadolescence. In sum, this study suggests that many children and adolescents contemplate suicide, that the risk of doing so begins to increase at an early age, and that clear similarities exist between those groups at heightened risk for suicidal thought and those at heightened risk for suicidal action. Moreover, this study illustrates the power of employing an analytic technique suitable for modeling transitions. Finally, it highlights the need to model differential influences on suicidal ideation at different stages in development. (Author abstract)