Background: Minerals deemed "critical" by USGS are both essential to U.S. economic or national security and have vulnerable supply chains. Supply chain vulnerabilities may arise from high U.S. reliance on imports or rapid growth in demand in the U.S. and abroad. Since USGS first issued its critical mineral list in 2018, the risk of critical mineral supply chain disruptions in the U.S. has grown, despite increased awareness of the issue. The USGS critical minerals list has grown from 35 minerals in 2018, to 50 in 2022, and 60 in 2025. Furthermore, as of Dec. 2025, the U.S. relied on imports for 100 percent of 14 of 60 critical minerals and had an import reliance of 50 percent or more for an additional 33 minerals. This import dependence increases risk to selected applications that use critical minerals, such as the semiconductor and battery industries. Building on previous GAO work (GAO-24-106395), this engagement will explore, if any, substitution and recycling technologies, that are available for deployment in 2-3 years, that may reduce this dependence. Key Questions: 1) What substitution or recycling technologies may reduce dependence on critical minerals in selected applications within the semiconductor and battery industries? 2) What are the challenges, if any, to the development and adoption of these technologies? 3) What policy options, if any, could support various policy goals?