This eBook brings together insights from six U.S. foundations that are formalizing more flexible and responsive grantmaking models. It highlights practices such as rapid response funds, out-of-cycle grants, multi-year commitments, and streamlined reporting processes. The publication emphasizes reducing administrative burden and aligning funding with real-time grantee needs. It also explores how non-monetary support, trust-based practices, and technology infrastructure strengthen grantee relationships. The report offers practical examples for grantmakers seeking to operationalize flexibility and trust in their strategies.