Preservice teacher performance assessments, such as the edTPA, are one of the accountability policies from states and local authorities designed to ensure the quality of beginning teachers and standardize teacher education. We studied experiences of 65 preservice teachers regarding the effect of the edTPA on their learning in field-placement classrooms. These cases revealed that the edTPA created "protected teaching spaces" for participants to experiment with student-centered instructional practices supported in university courses and codified in edTPA rubrics. This was especially impactful for novices who previously had limited opportunities to try out equitable reform-oriented instruction in their placements. In these cases, the edTPA also helped mitigate inequities in learning to teach, an unintended outcome that is important for policymakers to consider when deciding on credentialing requirements.