This document identifies potential incremental cost methodologies and measures that GCF can adopt in its project approval processes. The document examines the concept of incremental cost and its applications to climate change projects, in addition to current practices of other climate funds. Alternative methodology options are analysed to best meet the purpose of supporting project review and approval processes; guiding national designated authorities and accredited entities in project design and development; and improving GCF policies, including funding eligibility criteria and the results management framework.