The Washington Group Questions, specifically the short set (WG-SS), are increasingly used in humanitarian action. However practical challenges have led to confusion about whether and when the WG-SS can be most effectively used in emergencies. As part of a research partnership between Trinity College Dublin (TCD) and the UN World Food Programme (WFP), we evaluated the data processes and outcomes across WFP country offices in multiple countries, and for hundreds of thousands of aid recipients. This document presents 5 evidence-based criteria that can support decision-making as to whether to disaggregate data by disability, using the WG-SS.