Competency-based testing and credentialing (CBTC) initiatives aim to address inequity in adult education by fundamentally changing how states use GED®, HiSET®, and TASC™ test scores to award and withhold high school equivalency credentials. However, CBTC is inconsistent with how developers intend states to use those scores. Accordingly, it falls on states to evidence the validity of such interpretations. In the present study, I do just that -- analyzing the extent to which GED®, HiSET®, and TASC™ test scores reflect interchangeable measures of academic attainment for the purpose of credentialing high school completion. Findings suggest high alignment between these tests across all sources and types of validity evidence. This finding -- that CBTC-oriented use of GED®, HiSET®, and TASC™ test scores is valid -- may appear simple, but the policy implications are complex. Considerations range from how states should handle non-authorized test scores to how they can support stakeholders' understanding of those scores.