The U.S. Department of Energy (DOE) has completed a rulemaking to amend energy conservation standards for commercial water heaters. Now completed, this rulemaking fulfills DOE's statutory obligation under the Energy Policy and Conservation Act, as amended, (EPCA) to either propose amended energy conservation standards for commercial water heaters and hot water supply boilers (CWHs), or determine that the existing standards do not need to be amended. (Unfired hot water storage tanks and commercial heat pump water heaters are being considered in a separate rulemaking.) DOE must determine whether national standards more stringent than those that are currently in place would result in a significant additional amount of energy savings and whether such amended national standards would be technologically feasible and economically justified. In the final rule, DOE concludes, based on clear and convincing evidence that the standards adopted are technologically feasible and economically justified, and would result in significant additional conservation of energy. Specifically, with regards to technological feasibility, CWH equipment achieving the adopted standard levels are already commercially available for all equipment classes covered by the final rule. As for economic justification, DOE’s analysis shows that the benefits of the proposed standard exceed, to a great extent, the burdens of the adopted standards.