This paper highlights how accountability mechanisms and processes can play a vital role in driving progress on the Health 2020 and Sustainable Development Goals health equity commitments. Using concrete examples, it identifies how accountability mechanisms and processes assist countries in advancing on health equity and demonstrates how progress stalls when they are absent. It highlights how advancing on accountability requires engaging with multiple diverse actors at different levels in dynamic accountability processes, the importance of collecting and employing disaggregated data to underpin accountability processes and the potential of new accountability tools to address health equity. It demonstrates that progress on accountability requires state engagement with its health-related commitments, both within and beyond the health sector. The examples highlight that when such commitment is weak or absent, accountability suffers and progress on health equity is undermined.