The Defense Advanced Research Projects Agency (DARPA) seeks innovative approaches to address challenges related to quantum computing. The Quantum Benchmarking Initiative (QBI) aims to examine approaches for constructing a utility-scale fault-tolerant quantum computer and computational workflows that include quantum compute steps. Proposed research should investigate approaches that enable revolutionary advances in design, engineering, test, and evaluation of such systems. Specifically excluded is research that primarily results in evolutionary improvements to the existing state of practice. To rapidly capitalize on new opportunities, DARPA announces the QBI 2026 opportunity, which seeks specific solutions to targeted challenges related to developing utility-scale quantum computers, as defined in specific QBI topic (QBIT) calls. Each QBIT will (1) outline specific details regarding the research topic of interest and (2) provide proposal and submission instructions, including the due date for proposal submission, in addition to those outlined in this PA. Proposals must only be submitted in response to a QBIT. Proposals submitted directly to this PA will not be considered.