Using a life course approach, this study examines trajectories of religious participation from early adolescence through young adulthood. Distinct patterns of religious participation are identified, providing insight into how trajectories are shaped by family and religious characteristics and demonstrating the influence of life events on changes in religious participation. The study employs a group-based method of trajectory analysis, identifying three trajectories of stable religious participation (nonattendance, occasional attendance, and frequent attendance) and three trajectories of change (early, late, and gradual declining attendance). Residing with two biological parents and in a religious family increases the likelihood that youth attend religious services throughout adolescence. Religious disaffiliation is associated with lower religious participation for youth in all trajectories; marriage, cohabitation, and religious switching/conversion are associated with changes in participation among youth in the frequent and occasional attendance trajectories only.Recent studies suggest that religion is a significant part of life for many adolescents and young adults (Regnerus 2007;Smith and Denton 2005). Most youth believe in God; approximately half of all adolescents attend religious services regularly and believe that religion is a fairly important part of their lives (Smith and Denton 2005). Although these studies advance our knowledge about overall rates of youth religious involvement, less is known about how religiosity may change over time (Smith et al. 2003). It is generally believed that religious participation declines during adolescence and young adulthood and then increases later in adulthood as individuals marry and have children (Benson and King 2005; Stolzenberg, Blair-Loy, and Waite 1995; Uecker, Regnerus, and Vaaler 2007). However, youth may follow a variety of religious participation trajectories (Smith and Denton 2005).Two recent studies provide support for this argument. Regnerus and Uecker (2006) describe dramatic religious changes over a one-year period in adolescence, finding that religious change is more likely to occur in late adolescence (i.e., age 18) and that 5 percent of youth experience a large increase in religious participation while 6 percent of youth experience a large decrease in religious participation. Another study finds that 69 percent of youth attend religious services less frequently in young adulthood than in adolescence (Uecker, Regnerus, and Vaaler 2007). These studies provide some insight into the frequency of religious change among youth, but less is known about the ways in which these changes occur. Do youth experience a life-changing event that leads to a dramatic religious change, or does change occur more gradually? When is religious change most likely to occur, and what causes these religious changes during adolescence?Because religion is an important part of life for many youth, understanding whether youth follow a trajectory of religious stability or when and wh...