Interpretations for licensure tests involve a series of inferences or a validity argument, leading from the test score to decisions about who is accepted or denied entry into a profession. Utilizing an argument-based framework for validation based on the Standards for Educational and Psychological Testing, we explore the evidence for the ongoing use of the Performance Assessment for California Teachers (PACT) for Tier I licensure decisions. The evidence for a unidimensional and a multidimensional structure based on the instrument's content are examined with an item response model. Examining operational data (n = 1,711) from seven California teacher education institutions, we found sufficient internal structure validity evidence to support the continued, but limited, use of this instrument for its intended summative purpose. Evidence for a three-dimensional structure of model fit better explains overall teacher candidate performance on the PACT instrument as it is currently designed.