The progression of teacher learning from aspiring educator to accomplished practitioner is multifaceted and complex. Selecting a teacher preparation program is a critical point in this journey, but it is by no means the end. Strengthening teacher pipelines requires aligned systems that not only open diverse entry points and provide initial preparation but also create opportunities for ongoing growth and development. Teacher residencies are a model for coherent teacher development from preservice to teacher induction and beyond, through structured collaboration between universities and districts. Effective residencies are learning spaces that connect theory and practice in ways that center student and teacher learning. Residencies initiate and nurture professional learning communities that center shared values, critical reflection, powerful pedagogies, and networks of sustained, ongoing development and support. Contrary to some educators' assumptions, residencies are far more complex than simply increasing time in student teaching placements. An effective teacher residency depends on the hard work, commitment, and trust of partner institutions. UCLA-IMPACT (Inspiring Minds through a Professional Alliance of Community Teachers) is such a partnership between the UCLA Teacher Education Program and the Los Angeles Unified School District. The partnership between UCLA-IMPACT and Los Angeles schools has taught important lessons about how to better prepare STEM teachers to engage and persist in high-poverty urban spaces. This article describes how this model can improve teacher diversity and retention and even transform the culture and learning structures of schools.