There is no single answer to this question, and therefore no single way to do it. In The Lancet Global Health, Antonia Dingle and colleagues report the convening of a group of policy makers to discuss why we should track financing for RMNCH. The group developed a set of principles guiding what information an aid tracking tool would ideally include. The authors present this tool—the Muskoka2 method—for tracking RMNCH aid, along with estimates of RMNCH development assistance from 2002 to 2017