We, the U.S. Fish and Wildlife Service (FWS) and the National Marine Fisheries Service (NMFS) (collectively referred to as the “Services” or “we”), amend portions of our regulations that implement the Endangered Species Act of 1973, as amended (Act). The revised regulations clarify, interpret, and implement portions of the Act concerning the procedures and criteria used for adding species to the Lists of Endangered and Threatened Wildlife and Plants and designating and revising critical habitat. Specifically, the amendments make minor edits to the scope and purpose, add and remove some definitions, and clarify the criteria and procedures for designating critical habitat. These amendments are based on the Services' review of the regulations and are intended to clarify expectations regarding critical habitat and provide for a more predictable and transparent critical habitat designation process. Finally, the amendments are also part of the Services' response to Executive Order 13563(January 18, 2011), which directs agencies to review their existing regulations and, among other things, modify or streamline them in accordance with what has been learned.