Between December 2021 and late March 2022, CARE and five close allies led an ad hoc coalition advocating for US government approval of $17B in supplemental funding for global COVID-19 relief, specifically for resources to support vaccine delivery and front-line health workers. The purpose of this case study is to assess the effectiveness of the advocacy strategies employed by CARE and allies and draw out lessons to (1) inform future campaigning and (2) better integrate this type of assessment in CARE’s MEL activities.