In December, 2007, Congress passed and the President signed the Consolidated Appropriations Act (PL-110-61). This law included language which made the National Institutes of Health (NIH) Public Access Policy mandatory and compliance to it a statutory requirement. The law became effective April 7, 2008
and states the following:
The Director of the National Institutes of Health shall require that all investigators funded by the NIH submit or have submitted for them to the National Library of Medicine’s PubMed Central an electronic version of their final, peer-reviewed manuscripts upon acceptance for publication, to be made publicly available no later than 12 months after the official date of publication: Provided, That the NIH shall implement the public access policy in a manner consistent with copyright law.
The NIH Public Access Policy ensures that the public has access to the published results of NIH funded research. It requires scientists to submit final peer-reviewed journal manuscripts that arise from NIH funds to the digital archive PubMed Central upon acceptance for publication. To help advance science and improve human health, the Policy requires that these papers are accessible to the public on PubMed Central no later than 12 months after publication.
Policy details are available at http://publicaccess.nih.gov/policy.htm.