The U.S. Department of Energy has established long-term stewardship programs to protect human health and the environment at sites where residual contamination remains after site cleanup. At the Idaho National Laboratory Site, Comprehensive Environmental Response, Compensation, and Liability Act (CERLA) long-term stewardship activities performed under the aegis of regulatory agreements, the Federal Facility Agreement and Consent Order for the Idaho National Laboratory, and state and federal requirements are administered primarily under the direction of the Idaho Cleanup Project. It represents a subset of all on-going environmental activity at the Idaho National Laboratory Site. This plan provides a listing of applicable CERCLA long-term stewardship requirements and their planned and completed implementation goals. It proffers the Long-Term Stewardship Environmental Data Warehouse for Sitewide management of environmental data. This plan will be updated as needed over time, based on input from the U.S. Department of Energy, its cognizant subcontractors, and other local and regional stakeholders.