The California Teacher Residency Grant Program provided essential, one-time funding to jump-start new and to expand existing teacher residencies, which are pathways into the teaching profession that integrate a residents' coursework with a yearlong placement in the classroom of an expert teacher. In spring of 2021, WestEd collected data through the formative evaluation of the grant program to understand the extent to which grantee programs are building toward financial sustainability within the context of their one-time funding sources. The findings outlined in this brief indicate that the financial sustainability of programs is a critical challenge to address. Now is a crucial time to support California's residencies to engage in the intentional planning and partnership building that will ensure California's investment pays off for years to come.