This article makes a unique contribution to the literature on teachers' racialized sensemaking by proposing a framework of "ideology in pieces" that synthesizes Hall's (1982, 1996) theory of ideology and diSessa's (1993) theory of conceptual change. Hall's theory of ideology enables an examination of teachers' sensemaking as situated within a structured society and diSessa's research on conceptual change provides an analytical lens to understand the elements of ideological sensemaking and the processes of ideological transformation. I use the framework of ideology in pieces to analyze and interpret the ideological sensemaking and transformation of a teacher engaged in a collaborative teacher research group in which participants explored issues of social justice in their high school math and science classrooms. The framework and analysis presented in the article offer a more comprehensive theory of teachers' ideological sensemaking and transformation that includes their cognitive, social, and structural dimensions. (Contains 4 footnotes, 1 table, and 6 figures.)