In 2019, UNDP launched one of its most ambitious experiments in development: the UNDP Accelerator Labs. Ninety-one Labs across 115 countries were given an unusual mandate — to question assumptions, embrace uncertainty, and find new ways of doing development from the ground up. From Uncertainty to Insight: Open R&D for Sustainable Development is the story of what they built. Over six years the Labs surfaced grassroots innovations, empowered collectives, and harnessed data, evidence and local insights to accelerate progress. They co-created new value with over 2,500 partners across more than 100 countries. What began as an injection of fresh thinking into UNDP's development practice evolved into something larger: a globally distributed, open R&D function that turned community insight and local experimentation into new approaches for some of the world's most complex challenges. This 2025 Annual Report traces the six-year journey of the Accelerator Labs Network.