Our objective is to test-bed the new Expected Credit Loss (ECL) and Current Expected Credit Loss (CECL) models for bank credit loss accounting to identify the potential consequences of their implementation. In particular, whether and how ECL and CECL approaches could lead to divergence in credit loss accounting practices in the U.S. relative to the rest of the world is an unanswered question. To do this, we develop a stylized bank-loan setting in a controlled laboratory environment with eight different secured personal-loan portfolios. Fifty-six senior accounting students take the role of loan managers responsible for making annual loan-loss reserve decisions in a between-subjects design under the rules of either the ECL or CECL models. We examine the effects of mandating the ECL or CECL model in terms of their impacts on the adequacy of loan-loss reserves, the comparability and predictability of loan-loss reserves and the volatility of reported profit.