This case study summarizes the experience of the Charity & Security Network (C&SN), a diverse network of nonprofit organizations (NPOs) in the United States that sought to provide input on US anti-terrorist financing laws to the Financial Action Task Force (FATF) during its mutual evaluation of the US. The evaluation took place between early 2015 and December 2016, spanning a period of significant changes in FATF’s recommendation and guidance relative to NPOs. After describing C&SN’s efforts and assessing the experience, this paper makes several recommendations for FATF and NPOs to consider for future evaluations.