This article examines the transition to adulthood among 1.5-generation undocumented Latino young adults. For them, the transition to adulthood involves exiting the legally protected status of K to 12 students and entering into adult roles that require legal status as the basis for participation. This collision among contexts makes for a turbulent transition and has profound implications for identity formation, friendship patterns, aspirations and expectations, and social and economic mobility. Undocumented children move from protected to unprotected, from inclusion to exclusion, from de facto legal to illegal. In the process, they must learn to be illegal, a transformation that involves the almost complete retooling of daily routines, survival skills, aspirations, and social patterns. These findings have important implications for studies of the 1.5- and second-generations and the specific and complex ways in which legal status intervenes in their coming of age. The article draws on 150 interviews with undocumented 1.5-generation young adult Latinos in Southern California. (Contains 3 tables and 6 notes.)