This article provides a conceptual account and empirical analyses of the development of "boundary-crossing competence"--the ability to function competently in multiple contexts--using representative cases from two after-school programs with immigrant and low-socioeconomic status students. Our findings suggest that organizational designs that create networks of related communities of practice can provide opportunities for nondominant students to develop boundary-crossing competences through participation in expanded, horizontal--rather than hierarchal--systems of what Moll and colleagues have called "networked expertise." These new directions in understanding competence have important implications for improving learning designs for nondominant students. (Contains 14 footnotes and 1 table.)