This bill amends the Federal Power Act to establish a new framework for allocating the costs of certain significant electric transmission facilities. It authorizes entities proposing to own or operate these facilities to file tariffs with the Federal Energy Regulatory Commission (FERC) for cost allocation. The legislation specifically targets interstate electric power transmission lines and offshore electric power transmission lines , along with their necessary facilities. These facilities are designated as "transmission facilities of national significance" if they have a capacity of at least 1,000 megawatts, or an expansion increases capacity by at least 500 megawatts, and are completed after the bill's enactment. FERC is mandated to allocate costs to customers within applicable planning regions based on a cost causation principle , ensuring costs are roughly commensurate with a broad range of anticipated benefits. These benefits include reliability, economic, public policy, resilience, and environmental factors, aiming to facilitate the development of critical grid infrastructure.