This chapter develops a general validation framework for evaluating the impact of issues on the validity of credentialing tests. It outlines a general, argument-based approach to validation and specifies how credentialing test scores are typically interpreted and used. The chapter also outlines a validity argument for credentialing programs. The validity argument provides an evaluation of the proposed Interpretation/Use Arguments (IUA) and thereby provides a validation of the proposed interpretation and use of the test scores. The validity argument would start with a critical review of the IUA with particular attention to identifying any hidden assumptions or alternative plausible interpretations of the test scores. The test tasks included in credentialing tests are typically designed to assess command of the knowledge, skills, and judgment (KSJs), particularly those that are frequently required in practice and that are critical for effective performance in practice.