Despite questions about validity and reliability, the use of value-added estimation methods has moved beyond academic research into state accountability systems for teachers, schools, and teacher preparation programs (TPPs). Prior studies of value-added measurement for TPPs test the validity of researcher-designed models and find that measuring differences across programs is difficult. This study is the first to examine the reliability and usefulness of a value-added model for TPPs developed through a collaborative stakeholder process and mandated by state law for use in accountability. Based on the experience of developing a test-based metric for Texas TPPs, our results suggest that although value-added results are statistically robust, accountability status for individual programs is very sensitive to decisions about accountability criteria, the selection of teachers, and the selection of control variables.