This bill, known as the "Next-Generation Geothermal Research and Development Act," aims to significantly bolster the development and deployment of advanced geothermal energy technologies by amending the Energy Independence and Security Act of 2007. It introduces new definitions for closed-loop geothermal systems , next-generation geothermal systems (encompassing enhanced, closed-loop, and supercritical conditions), and supercritical geothermal , clarifying the scope of future research. The legislation directs the Department of Energy to expand research and development activities, including the use of machine learning algorithms for hydrothermal research, and to enhance a public repository for geothermal data. This repository will be periodically updated, standardized, and made more accessible, incorporating publicly available subsurface data from various operations. A key provision requires the Secretary of Energy to enter into a memorandum of understanding with the Secretary of the Interior and other federal departments for sharing geothermal development data, prioritizing heat, lithology, and strain profiles. The Secretary of the Interior is also authorized to commission drilling of supercritical geothermal exploration boreholes and conduct studies on site selection characteristics, including in U.S. territories. The bill renames and expands the existing enhanced geothermal systems research section to focus on "Next-Generation Geothermal Systems Research and Development." It establishes a dedicated program within the Geothermal Technologies Office to support research, development, demonstration, and commercial application activities, with a focus on topics like well completion, permeability management, materials development for supercritical systems, and deep drilling. The program prioritizes projects that produce iterative data for deep drilling in unique geodynamic settings and allows for grants to higher education institutions and private sector entities. A report on water use and estimated needs for various geothermal systems, including the ability of next-generation systems to use brackish water, is also mandated. Furthermore, the bill establishes a Next-Generation Geothermal Center of Excellence through competitive grants to National Laboratories, multi-institutional collaborations, public-private partnerships, or higher education institutions. This center will coordinate R&D, foster collaboration, support workforce development, and provide technical assistance to advance next-generation geothermal technologies. To accelerate commercialization, the bill creates Commercial-Readiness Innovation Grants for innovative technologies that improve the performance of commercial geothermal projects. These grants prioritize applicants with expertise in field development and projects with the greatest ability to advance near-term commercial deployment of enhanced and closed-loop geothermal systems, particularly in diverse geological or supercritical conditions, with a federal cost share of up to 80 percent. The bill authorizes an appropriation of $150,000,000 for each of fiscal years 2027 through 2031 for these activities. It also mandates quadrennial updates to the geothermal resource assessment by the U.S. Geological Survey, with the first update due within two years of enactment, to include the potential for supercritical geothermal resources across the United States and its territories.