Stress tests are conducted frequently, and they disclose valuable information about the bank. A credible stress test design must account for stakeholders’ strategic responses to the test results and that any bank passing a test will not fail thereafter. We build a dynamic coordination framework to study the optimal design of credible stress tests. Higher testing frequency reduces the need for greater stringency, enlarging the set of credible designs. We identify the optimal mix of test frequency and stringency and show how it depends on macroeconomic conditions, the bank’s systemic importance, private incentive distortions, administrative costs, and liability asynchronicity.