Phase 2: Expansion of the NIH Preprint Pilot and How to Report Preprints

The NIH Preprint Pilot began in June 2020 as a project by the National Library of Medicine (NLM) to make COVID-19 research discoverable in PubMed Central (PMC). In Phase 1 of the project, over 3,300 preprints reporting NIH-supported COVID-19 research were added to PMC and viewed 4 million times. Building on the success of Phase 1, the NLM is now expanding the pilot.

In Phase 2, preprints that acknowledge direct NIH support and/or have an NIH-affiliated author and are posted to an eligible preprint server Jan. 1, 2023 or later will be included in PMC. All works in PMC have a PubMed Central Identifier (PMCID).

The four eligible preprint servers include: bioRxiv, medRxiv, arXiv and Research Square.

When you are preparing preprints please,

    1. In the text of the document:
      • Clearly state that the work is not peer-reviewed.
      • Declare any competing interests, as an author would do for any journal article.
      • Acknowledge NIH funding in accordance with NIH Grants Policy Statement Chapter 8.2.1.  Per the NLM: “Preprints that do not clearly acknowledge direct NIH support will be considered out of scope” and will not be included in PMC.
    2. Consider open license options. “The NIH strongly encourages awardees to select a Creative Commons Attribution (CC-BY) license or dedicate their work to the public domain.” See:
      NIH NOT-OD-17-050: Reporting Preprints and Other Interim Research Products, for more information.

    When you are reporting preprints, remember

    1. Preprints can be included on a Research Performance Progress Report (RPPR).
      Investigators have the option to include preprints on their RPPR. While the NIH has encouraged researchers to report preprints since 2017, it is not required.

      Phase 2 will make including preprints on an RPPR easier as they can be added to My Bibliography from PubMed. Once added to an investigator’s My Bibliography, preprints can be associated with NIH funding and will then display in the RPPR module.

      Preprints not found in PubMed, such as those submitted to eligible servers before Jan. 1, 2023 or those submitted to other preprint servers, can still be added to My Bibliography using the “Add citations manually” option and selecting the “Preprint” template. See My Bibliography: Adding Citations Manually for guidance or watch this video from NLM.

    2. Preprints are exempt from the NIH Public Access Policy.
      As shown in the graphic from the NLM below, preprints are not peer-reviewed.

      NLM Graphic

      Image from: Retrieved Feb. 10, 2023.

      One of the three criteria of the NIH Public Access Policy is that a work is a peer-reviewed journal article. Preprints are not peer-reviewed and are exempt from the NIH Public Access Policy, and therefore, no PMCID is required.  While Phase 2 of the NIH Preprint Pilot makes it much more likely that preprints arising from NIH funding will be discoverable in PMC and have a PMCID, they are still exempt from the NIH Public Access Policy.

    More information on preprints and the NIH Preprint Pilot: