ABSTRACT Transformational adaptation is increasingly viewed as necessary to prevent the worst offsets in development gains due to severe climate impacts. However, clarity regarding how to produce transformational adaptation in practice is lacking, creating problems for project design and implementation. This paper examines (1) how transformational adaptation has been defined by major funders of adaptation; (2) how the concept has influenced funding priorities and the financing of projects. The study is based on a comparative analysis of the investment criteria, board meeting minutes, documents, and reports of the primary financial mechanisms under the United Nations Framework Convention on Climate Change: the Least Developed Country Fund, the Special Climate Change Fund, the Adaptation Fund and the Green Climate Fund. Our study demonstrates an increasing emphasis on transformational adaptation across funds over time, particularly in the Green Climate Fund. Transformative potential does guide funding decisions, but a clear understanding of whether transformational change is achievable, feasible, and desirable under all conditions has not yet emerged, an issue acknowledged by the funds and regularly discussed. Our analysis suggests that acknowledging tensions which arise with transformation in adaptation finance is critical because investment criteria and definitions of transformation impact the approaches to adaptation countries take.