The “intergenerational transmission” of heritage languages (HLs) is crucial to the vitality of heritage language communities (especially for indigenous communities, where immigration is not a source of new speakers). We know, however, that HLs in the United States often do NOT survive well from one generation to the next as the shift to English takes place. In conjunction with the Second National Conference on Heritage Languages in America, a small group of researchers met to discuss priorities for research on intergenerational transmission of languages. Each of the ten researchers who participated prepared a short paper, posing research questions with some commentary to guide future research. Those papers form the major part of this article, covering topics related to language ecological patterns (in communities, families, and institutions), language ideology, measurement issues, and literacy.