This report presents the findings of an Independent Evaluation Unit (IEU) desk-based assessment of the Green Climate Fund (GCF) portfolio, examining the evaluability of funded activities. It builds on insights from three previous assessments conducted in 2019, 2022, and 2024, offering a longitudinal perspective on progress and persistent challenges. The assessment pursues two core objectives. First, it evaluates the quality of approved and ongoing funding proposals (FPs), with the aim of supporting project developers and managers to draw lessons from past experience and design stronger, more results-oriented proposals with a higher likelihood of achieving measurable outcomes. Second, the study seeks to inform the refinement of GCF investment criteria, embed evidence-based learning within GCF projects and processes, and strengthen the effective implementation and overall impact of GCF resources.