This document analyzes compliance with open access mandates by major research funders. It finds that compliance levels vary significantly by funder, discipline, and whether access is provided through gold or green open access. Funders in the biomedical field have the highest compliance rates, while those in the social sciences and humanities have the lowest. Compliance has increased overall in recent years, but green open access is more common than gold. The authors recommend that funders focus on standardizing embargoes, improving self-archiving infrastructure, shifting scholarly cultures, and addressing affordability of article processing charges to further increase open access to published research.