NIH requires that the peer-reviewed articles it funds be made publicly available on PubMed Central (PMC). The NIH Public Access Policy requires authors to submit the final peer-reviewed manuscripts that arise from NIH funds to PMC upon acceptance. Papers must be accessible on PMC no later than 12 months after the official date of publication. It is important to plan the method that your articles will be entered into PMC. This method will change depending on the journal publishing the article.
There are 4 ways that articles can be added to PMC:
Method C and D Journals
These journals require steps on behalf of the publisher (Method D) or author (Method C) to deposit the manuscript into the NIH Manuscript Submission System (NIHMS). Read more about the steps required (guide from UCSF Library).
If your article is non-compliant, i.e. does not have a PMCID, the authors or PI will need to address the compliance issue: