The Agency for Healthcare Research and Quality, an agency within the United States Department of Health and Human Services, has adopted an open access mandate.
Here's an excerpt:
For scholarly publications, the AHRQ Public Access Policy will require that authors submit the final peer-reviewed accepted journal manuscripts to PubMed Central (PMC). In lieu of the final peer-reviewed manuscript, AHRQ will accept the final published article, provided the awardee can ensure AHRQ has the rights to make the published version public. AHRQ's Public Access Policy is subject to law; Agency mission; resource constraints; U.S. national, homeland, and economic security; and the objectives listed in the OSTP directive.
To the extent feasible and consistent with applicable law and policy; Agency mission; resource constraints; U.S. national, homeland, and economic security; and the objectives listed below, digitally formatted scientific data resulting from unclassified research supported wholly or in part by Federal funding should be stored and publicly accessible to search, retrieve, and analyze. For sharing of data in digital format, all AHRQ-funded researchers will be required to include a data management plan for sharing final research data in digital format, or state why data sharing is not possible.
Peter Suber has critiqued the mandate.