Starting on July 1, 2013, for non-competing continuation grant awards, NIH will delay processing if publications arising from it are not in compliance with the NIH Public Access Policy.
Articles resulting from NIH funding that have been published since April 2008 must be in PubMed Central (PMC) to be compliant.
On August 25, 2022 the White House Office of Science and Technology Policy (OSTP) issued updated policy guidance directing federal agencies to expedite access to results of federally funded research. The results of taxpayer-supported research will be immediately available to the American public at no cost. In a memorandum to federal departments and agencies, Dr. Alondra Nelson, the head of OSTP, delivered guidance for agencies to update their public access policies as soon as possible to make publications and research funded by taxpayers publicly accessible, without an embargo or cost. All agencies will fully implement updated policies, including ending the optional 12-month embargo, no later than December 31, 2025.
If you find that you have non-compliant citations, you will need to submit them to PMC. There are four different submission methods. The method you use will depend on the journal/publisher associated with each citation.
The NIH Public Access website offers overviews of the policy and the recent changes, along with help documents.