To support young people making the transition to adulthood from a substitute living environment (youth-in-care), several countries have developed specific programs. Systematic reviews and meta-analyses that have examined the effectiveness of these programs find that the use of non-experimental designs in the majority of single evaluation studies prevents conclusions from being drawn on the topic. The present study is a meta-analysis that assesses the effectiveness of child-welfare programs aiming to prepare youth transition to adulthood, selecting only studies that use an experimental or quasi-experimental design. A total of k = 9 studies (n = 7,127) conducted in the United States and published between 2010 and 2019, inclusively, were selected. Weighted effect sizes for the dimensions of employment, housing and social network were measured. The results indicate that the programs have a very small effect favouring the treatment group for the dimensions of employment (k = 5, n = 5,778) and housing (k = 5, n = 2,467), one to four years after time zero. No significant effect was observed for the dimension of social network (k = 5, n = 1,797). Given the complexity of youth-in-care needs, it is recommended that services be extended beyond the age of majority to prepare for the transition to adulthood, that an interdependent and multidimensional view of this transition be promoted, and that research with sound specifications be conducted to support service improvement.