The TAAP Act reauthorizes and updates a program that assesses shared groundwater resources between the United States and Mexico. The bill expands the program to include Arizona in addition to New Mexico and Texas, though it excludes a specific aquifer in the Yuma groundwater basin. It extends federal funding authorization for the program from the previous 2007-2016 timeframe to fiscal years 2026 through 2036, ensuring a decade of continued support. The legislation affects states along the U.S.-Mexico border that depend on transboundary aquifers for water supplies and will enable ongoing scientific assessment and monitoring of these shared water resources.