States differ in the ways in which older youth exit from foster care. States such as Texas, California and Wisconsin require youth to exit the foster care system by age 18 or when they complete high school. Many other states such as New York, Maryland and Illinois allow youth to stay in the foster care system until age 21. Recent work from the Midwest Study of Adult Functioning of Former Foster Youth compared youth who left the foster care system between ages 17 and 19 with those who remained and found evidence that remaining in care was beneficial for youth on several dimensions (Courtney & Dworsky, 2006). This has led to a renewed call to increase the age of foster care exit to age 21 in some states. Little research, however, has examined the older youth foster care transition in states where youth can remain in care past age 18. This article uses research from Missouri, where older youth can stay in the foster care system until age 21; to address several different questions about the phenomenon of transitioning out of the foster care system between ages 17 and 19. Quantitative methods will be used to address three questions. Who exits before age 19 and who stays? When do they exit? Where do they go? Qualitative methods will be used to address two complementary questions. What are the circumstances of their exits? Do they want to exit and if so, why?