Guide

PMC Requirements for Open Access Journals

Practical guide to PubMed Central requirements for open access journals: NIH policies, JATS metadata, licenses, and deposit workflow.

PubMed Central (PMC) is the free full-text archive of biomedical and life sciences literature maintained by the U.S. National Library of Medicine (NLM), which is part of the National Institutes of Health (NIH). It is not simply "the NIH open access repository": PMC hosts both immediate open access content and articles under an authorized embargo, so not all content deposited in PMC is open access at the time of publication. For Latin American journals in health sciences and related disciplines, PMC indexing —and visibility in PubMed— represents a qualitative leap in international discovery. This guide summarizes the technical and editorial requirements an open access journal must meet to participate in PMC.

Journal participation agreements with PMC

A journal that formally participates in PMC signs one of three participation agreements:

Agreement	Description
Full Participation	All of the journal's research articles are deposited in PMC.
NIH Portfolio	The journal deposits NIH-funded articles, starting from an agreed volume/date.
Selective Deposit	The journal deposits a selected subset of articles it designates, short of Full Participation coverage.

These three agreements are distinct from NIHMS (the NIH Manuscript Submission system): NIHMS is the technical deposit mechanism an individual author uses to submit an accepted manuscript (AAM) in order to comply with the NIH public access mandate — it is not a fourth type of journal participation agreement. A journal can have no participation agreement with PMC at all and still see its authors' manuscripts deposited via NIHMS.

Journals seeking sustained PMC presence generally choose Full Participation or an NIH Portfolio agreement, depending on how much of their content is NIH-funded.

Editorial eligibility criteria

Before applying for PMC review, a journal must meet criteria that NLM distinguishes as mandatory requirements, expectations, or recommendations:

Criterion	Type
Registered ISSN (print and/or electronic)	Mandatory
Minimum of 25 peer-reviewed research articles published prior to applying	Mandatory (pre-application requirement)
Sustained editorial quality track record, generally on the order of about 2 years of continuous publication	Expectation
Documented scientific and editorial review process	Mandatory
Technical quality of content (full text, not just abstracts; legible figures and tables)	Mandatory
Content in English, or English-language metadata/abstract when the primary language is other than English	Recommendation (per NLM language guidelines)

These criteria are evaluated during PMC's formal application process, independent of which participation agreement is chosen.

Open access editorial requirements

For an open access journal seeking to participate in PMC, deposited content is expected to be available as immediate open access. PMC, as an archive, also accepts content under explicit embargo for certain participation agreements (for example, hybrid or subscription journals under Full Participation), but that pathway does not apply to the pure open access journal profile this guide addresses. For new journals:

Documented open access policy on the website.
Creative Commons or other compatible license (CC BY preferred for maximum reuse).
Valid ISSN (print and/or electronic).
Transparent peer review process.
Full content availability without paywalls.

Declare the license in JATS:

<permissions>
  <copyright-statement>© 2026 The authors</copyright-statement>
  <license license-type="open-access"
          xlink:href="https://creativecommons.org/licenses/by/4.0/">
    <license-p>Distributed under CC BY 4.0.</license-p>
  </license>
</permissions>

XML format: JATS for PMC

PMC recommends the JATS Journal Publishing Tag Set, together with the PMC Tagging Guidelines and its Minimum Data Criteria, as the preferred deposit format. The document must include complete metadata in <front>, structured body in <body>, and references in <back>.

Root element with mandatory attributes:

<article xmlns:xlink="http://www.w3.org/1999/xlink"
         xmlns:mml="http://www.w3.org/1998/Math/MathML"
         article-type="research-article"
         dtd-version="1.4"
         xml:lang="en">

Critical metadata for PMC

DOI in <article-id pub-id-type="doi"> (without URL prefix).
Authors with affiliations linked via <xref ref-type="aff">.
NIH funding when applicable, in <funding-group> with <award-id>.
Structured abstract with sections when the journal uses them (Background, Methods, Results, Conclusions).
Keywords aligned with MeSH when possible.

<funding-group>
  <award-group>
    <funding-source>
      <institution-wrap>
        <institution>National Institutes of Health</institution>
      </institution-wrap>
    </funding-source>
    <award-id>R01-GM123456</award-id>
  </award-group>
</funding-group>

NIH public access policy

NIH has two generations of public access policy, and the date distinction matters for journals:

Historical policy (since 2008): author accepted manuscripts (AAMs) resulting from NIH funding had to be available in PMC within a maximum of 12 months of publication — i.e., an embargo of up to one year was permitted.
NIH Public Access Policy (2024), effective July 1, 2025: AAMs accepted for publication on or after that date must be made publicly available in PMC without embargo, no later than the Official Date of Publication. Applicability is determined by the manuscript's acceptance date, not by whether the grant is "new": it applies to both new and ongoing NIH awards, provided the manuscript is accepted on or after July 1, 2025.

In practice, journals publishing NIH-funded research must:

Identify NIH funding in metadata (<funding-group> with <award-id>).
Track and communicate the manuscript acceptance date accurately, since it determines which policy applies.
Facilitate deposit of the accepted manuscript (AAM) or final version, without embargo when required by acceptance date.
Maintain persistent links between DOI and PMC record.

Omissions in <funding-group> create mandate non-compliance and may affect authors' future grants.

Equations and technical content

PMC prefers equations in MathML within <disp-formula> or <inline-formula>. Equation images without semantic markup reduce accessibility and may generate warnings in technical review.

<disp-formula id="eq1">
  <label>(1)</label>
  <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
    <mml:mi>E</mml:mi><mml:mo>=</mml:mo><mml:mi>m</mml:mi><mml:msup><mml:mi>c</mml:mi><mml:mn>2</mml:mn></mml:msup>
  </mml:math>
</disp-formula>

Bibliographic references

PMC favors <element-citation> with reference DOI in <pub-id pub-id-type="doi">. Incomplete references hinder linking in PubMed and reduce citation metrics.

Review the malformed references guide and validate the complete batch before deposit.

Pre-deposit validation

Before submitting to PMC:

Validate JATS structure (the JATS validator checks JATS Archiving 1.4; that alone is not sufficient for PMC) and review the document against the PMC Tagging Guidelines and Minimum Data Criteria.
Verify affiliations, ORCID, and funding.
Confirm figures and tables have unique IDs and associated files.
Review license and publication dates.

Invalid document structure or missing required attribute errors block automated processing.

Typical deposit workflow

Article published open access
    ↓
Complete JATS (Journal Publishing) generation
    ↓
Internal validation (JATS + PMC Tagging Guidelines)
    ↓
Deposit via NIHMS or publisher agreement
    ↓
PMC review / corrections
    ↓
Availability in PMC and link from PubMed

Plan 10–15 business days for the first technical review of a pilot batch.

Differences from SciELO SPS

Both PMC and SciELO build on the JATS Journal Publishing Tag Set but apply different rules and guidelines of their own:

Aspect	PMC	SciELO SPS
NIH funding	Must declare	Not applicable
License	CC preferred	CC mandatory
Abstract language	English common	Per collection
MathML	Highly recommended	Per discipline

Journals indexed in both systems must produce XML satisfying the most restrictive rule set or maintain separate export profiles.

Support services

EditorialXML JATS XML production includes normalized metadata, structured references, and pre-deposit validation. For editorial review beyond schema checks, see editorial validation.

Conclusion

PMC requirements are not exclusive to North American journals: any open access journal publishing relevant biomedical research that meets NLM's eligibility criteria can benefit from PMC deposit. Investment in JATS valid against the Journal Publishing Tag Set and PMC Tagging Guidelines, complete funding metadata, and clear licenses translates into PubMed visibility and NIH mandate compliance for your authors.

Start by validating a pilot article in the JATS validator and review the complete JATS XML guide for standard fundamentals.