The Public Access Policy was established by the White House Office of Science and Technology (OSTP) with the goal of increasing public access to the results of federally funded research. Sixteen federal agencies have responded to this policy. For example, the National Institute of Health has adopted the policy that all articles published as a result of research funded by the NIH must be published in PubMed Central no later than 12 months after publication.
Links to the government agencies and their public access policies:
Of interest:
Memorandum for the Heads of Executive Departments and Agencies
2016 Update:Increasing Access to the Results of Federally Funded Science