What is the connection between PubMed Central (PMC) and the NIH Public Access Policy?

Since its creation in 2000, PubMed Central (PMC) has served as a free digital archive of full-text biomedical and life sciences journal literature at the U.S. National Institutes of Health (NIH). PMC is developed and managed by NIH’s National Center for Biotechnology Information (NCBI) within the National Library of Medicine (NLM).

Since 2005, PMC has also been the designated repository for papers submitted in accordance with the NIH Public Access Policy and for those that fall under similar policies from other funding agencies.

How are articles submitted to PMC?

Final, published articles are supplied to PMC only through publishers who have formal PMC participation agreements.

Author manuscripts must be submitted through either the NIH Manuscript Submission System (NIHMSS) or its equivalent in the UK, the UKMSS. The NIHMSS allows for the deposit of individual manuscripts in compliance with the NIH Public Access Policy. Papers funded by The Wellcome Trust, or by other funding agencies in the UK, should be deposited through the UKMSS.

Author manuscripts may be deposited by either an author or by a publisher on behalf of an author, but only via the NIHMSS or the UKMSS. Please note that these two submission systems are the only means by which an individual author may submit a paper to PMC.

What is the relationship among the following article identifiers: PMCID, NIHMSID, and PMID?

The PMCID is a unique reference number that is automatically assigned to every article that passes successfully through PMC’s production system. The PMCID is also used for citation purposes as part of the NIH Public Access policy. The PMCID can be found in both PMC and in PubMed citations (see examples below).

View of PMCID for an Author Manuscript from PMC Search Result

View of PMCID for a Final, Published Article from PMC Search Result

The NIHMSID is a preliminary article identifier that applies only to manuscripts deposited through the NIHMSS. Once the paper appears in PMC, it will also be assigned a PMCID.

View of PMCID and NIHMSID for an Author Manuscript in PMC

View of PMCID for Final, Published Article in PMC

The PMID is the unique identifier for PubMed citations. The PMID is a distinctly different reference number from the PMCID and is used only for PubMed records.

PMID and PMCID in PubMed Citation

However, the PMID can be used to find the corresponding PMCID (or NIHMSID) if these reference identifiers have already been created. This type of search is possible by using a special tool called the PMID to PMCID Converter.

How do I find PMCIDs for embargoed articles?

You can find embargoed article citations and their corresponding PMCIDs through a PMC search option. Using the Limits tab, click in the field, “Show both free and embargoed articles” to obtain the search result for both article types.

Search Option for Embargoed Article Citations

After locating the article, you will see the PMCID at the bottom of the citation, as well as the date on which the article will become publicly available or “Free in PMC”.

Embargoed Article Citation from PMC Search Result

You can also find the PMCID for an embargoed article in the abstract view of the citation in PubMed.

Embargoed Article Citation in PubMed

What is the difference between the PMC Journal list and the NIH Public Access Policy Journal list?

The PMC Journal List offers a view of all the journal titles that have deposited or are currently depositing final, published articles into the PMC archive. The list includes information about what content is available from each journal, as well as links to that content (see also FAQ (#10).

A journal title will appear on the PMC journal list only when the journal’s articles are publicly available in PMC.

The NIH Public Access Policy Journal List comprises those journal titles that deposit the final, published versions of all NIH-funded articles in accordance with the NIH Public Access Policy. In contrast with the PMC journal list, the NIH PA list may include journals whose articles are not yet viewable in PMC because of publisher embargos.

How can I, as a publisher, ensure that my journal title is on the NIH Public Access Policy Journal list?

In order for a journal title to appear on the NIH Public Access Policy Journal list, a publisher must have a formal publisher participation agreement stipulating that you will deposit either the complete contents of a journal or, at a minimum, all the NIH-funded articles that are included in the journal.

When will my journal appear on the NIH Public Access Policy Journal list?

Your journal will appear on the NIH Public Access Policy Journal list after PMC has determined that the journal submissions meet PMC’s standards for editorial quality and technical production.