Creates a dedicated Treasury fund for the Southwestern Power Administration and sets clear rules for what money goes in, how it can be spent, and when excess money must be returned to the Treasury. It lets the agency use the fund for transmission operations and maintenance, power marketing, building transmission lines and related facilities, and administrative costs.

Money flowing into the fund includes agency receipts, appropriations, and certain transferred balances. The agency may incur obligations in anticipation of these resources, improving cash flow for day‑to‑day operations and projects. Any year‑end surplus must be transferred back to the Treasury. The bill also updates prior appropriations language to align with this new fund. It defines key terms used in the Act (Administrator, Fund, and Secretary).