NOAA Fisheries will propose designating critical habitat for the threatened Nassau grouper pursuant to section 4 of the Endangered Species Act (ESA). Specific occupied areas under consideration as critical habitat for this species include approximately 2,352.27 sq. kilometers (908.22 sq. miles) of marine habitat located in waters off southeastern coast of Florida, Puerto Rico, Navassa, and the United States Virgin Islands (USVI). For this critical habitat designation, the incremental costs of the proposed rule are anticipated to be limited to the additional administrative effort required for section 7 consultations to consider impacts to the critical habitat. We have contacted the Departments of the Navy, Air Force, and Army as well as the U.S. Coast Guard requesting information related to potential national security impacts that may result from the critical habitat designation. Based on information they provided, national security impacts are not expected to arise as a result of this rule. NMFS also contacted the Department of Defense (DoD) to determine if any areas controlled by the DoD coincide with any of the areas under consideration for critical habitat, and none were found that would result in not designating critical habitat pursuant to section 4(a)(3)(B)(i) of the ESA.  This rule is consistent with existing critical habitat regulations in the application of the ESA.