The U.S. National Institutes of Health (NIH) has a public-access policy for research that it funds.
This requires investigators to submit papers arising from NIH-funded research to the PubMed Central repository as soon as they are accepted for publication.1
The papers must then be freely accessible to the public within 12months of publication. However, this currently only has a compliance rate of 75%.
On 16November 2012, the NIH announced next year (beginning as soon as spring 2013), it would withhold the future grant instalments from recipients who have not complied.2
Ensuring that publically funded research is freely accessible is a major step towards the democratisation of medical literature. This should parrallel the broader involvement of patients at all stages of their care.
The UK Research Council has a similar policy -- sometimes requiring open access within six months -- but it is unclear how well this is currently implemented.3
Links to other websites are current at date of posting but not maintained.