Too often teacher professional development (PD) is focused on mainstream K-12 learners, even as US schools become more culturally and linguistically diverse (CLD). This theoretical paper provides guidance for centering professional development on the margins. The three conclusions are distilled from robust experiences with middle and high school K-12 educators. They include making PD relational, providing ample time and patience for teachers to change underlying beliefs, and grounding PD in authentic inquiry, rather than indulging a strategy fetish.