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How to Join PMC

This page describes the process for adding a journal to PubMed Central (PMC) and explains what is required of participating journals. Interested publishers should also read the PubMed Central FAQs and the Deposit and Access Policies. Although PMC currently focuses on archiving English-language journals, NLM recognizes the need to include other languages in the archive and intends to do so gradually. For more information, see the FAQ on PMC support for languages other than English.

Participation in PMC is open to any life sciences journal that meets NLM's standards for the archive. A journal must qualify on two levels: the scientific quality of the publication and the technical quality of its digital files.

A journal meets PMC's scientific quality standard if it has been selected for the NLM collection by NLM’s Selection and Acquisitions section. See the NLM Technical Services Division fact sheet for more information about this NLM group and NLM's collection development policy.


Technical Requirements for PMC Journals

Required Files

A journal must provide PubMed Central the full text of articles in an XML (eXtensible Markup Language) or SGML (Standard Generalized Markup Language) format that conforms to an acceptable journal article DTD (Document Type Definition). PMC does not accept articles in HTML format.

The original high-resolution, digital image files must also be provided for all figures. A PDF, if one exists, should be submitted in addition to the XML/SGML version (but not as the only form) of an article. Supplementary material, in the form of video, audio or data files that may be available with an article, should also be submitted.

NLM has a Journal Publishing XML DTD that any journal may use to submit its data. PMC will also accept data in other full-text article DTDs that are widely used in life sciences journal publishing.

See the PMC File Submission Specifications for details about required data elements and file formats as well as instructions for naming, packaging and delivering files to PMC.

Evaluation of Sample Files

Before accepting a journal into PMC, NLM must be sure that the journal can routinely supply files of sufficient quality to generate complete and accurate articles online, without the need for human action to correct errors or omissions in the data. For this evaluation, the journal must provide PMC all applicable files for a representative set of articles and issues.

A typical sample set for a journal that has been in existence for more than a few years is 3 issues or approximately 50 articles. Smaller samples are acceptable for relatively new or small journals. In all cases, the sample must be representative of the variety of publications styles and file formats found in the journal. Among the variations that should be represented are special issues or supplements, articles or other items that deviate from the typical style and structure of an article, and changes in publication style or format that have occurred over time.

The sample set should include:

  • A separate XML/SGML data file for the full text of each article or other published item.
  • The original high-resolution, digital image files for all figures in an article.
  • A PDF, if available, for each article.
  • Any supplementary data files (e.g., spreadsheets or video files) that are available for an article.
In certain cases, PMC may also ask for a copy of the applicable DTD, with documentation.

PMC will check the sample data to ensure that:

  • all required files have been supplied and are correctly named
  • the XML/SGML parses correctly according to the DTD
  • the online presentation of an article, as generated from the XML/SGML and associated image files, is an accurate and complete rendering of the article.
This last check is made against the print or PDF version of an article or, in cases where content is only available online, against the copy of the article at the journal's own site.

The publisher is expected to correct any errors found during the evaluation and repeat the evaluation process before proceeding to the next step.


Prerequisites for Newly Created Journals

In the case of a journal that has just begun publishing or has not yet published any articles, please note the following:

  1. The journal must have a properly registered ISSN before making any kind of application to PMC. This means that there must be a record for the journal in the official Register of the ISSN International Centre.
  2. The journal must have a reasonable number of published articles in order for NLM to make a decision about its scientific quality.
  3. The journal must have at least 10 published articles that pass PMC's technical evaluation of data files before the journal can actually appear on the PMC site. PMC may relax this requirement, at its discretion, in cases where a publisher has a consistent history of making problem-free deposits for other journals in PMC.

The PMC Application Process

To begin the process, the journal publisher should send an email to pmc@ncbi.nlm.nih.gov indicating what it wishes to include in PMC. For each journal, provide at least:

  • The full name and ISSN of the journal.
  • A URL for the journal site, if the journal is online.

After a brief review, PMC will inform the publisher whether or not the journal meets PMC's scientific quality standard. For journals that meet this standard, the process will continue as follows:

  1. The publisher sends PMC a representative set of files for evaluation.
  2. PMC reviews the files and sends back a report specifying what needs to be corrected. The publisher corrects the problems and resubmits the sample for evaluation. Note: If, on the third submission, there are still problems, the journal's application will be rejected.
  3. If the sample set is satisfactory, PMC will ask the publisher to send in a complete set of files for all issues up to the present that are to be included in the archive. (If the journal is going to be providing files for a large number of back years, PMC may ask for them to be delivered in installments, usually a year at a time.) Prior to sending these files to PMC, the publisher must correct all data problems similar to those that were found in the sample set.
  4. If PMC finds significant data problems in the publisher's full set of files, the journal's application may be rejected.
  5. Assuming that the files provided by the publisher are problem-free, PMC sets up the journal on a preview site for the publisher to review. PMC corrects any problems on its end that may be found in this review.
  6. The publisher and NLM complete a formal PubMed Central Participation Agreement.
  7. The journal is released to the PMC public site.

Journal Setup Requirements

The PubMed Central online presentation style allows a journal to maintain a distinct identity, but it also provides consistency of appearance and functionality across all of PubMed Central, for the benefit of users.

The journal identity is set by the journal banner at the top of each page and a journal 'watermark' stripe running the length of each page. The journal banner is also used to provide a link (or links) back to the journal's own site. Within the general PMC template, a journal may choose from a number of styles for presenting elements such as references, section headings and certain parts of the article front matter.

See the PMC Journal Setup Requirements for details. Do NOT send in any setup information until PMC asks you to do so.

PMC Participation Agreements

Before a journal is released publicly in PMC, the publisher must complete a formal PubMed Central Participation Agreement with NLM. There are three types of agreements, which correspond to how much content a journal plans to deposit. Click on the links below to get a copy of the respective agreement in Microsoft Word format.

  • Full Participation: the journal commits to depositing the complete contents of each issue or volume, starting with a particular volume/issue or publication date.
  • NIH Portfolio: the journal commits to depositing all NIH-funded articles (as defined by the NIH Public Access Policy), starting with a particular volume/issue or publication date. The journal may choose to also deposit other, non-NIH-funded articles under this agreement.
  • Selective Deposit: generally used by publishers who offer a hybrid publishing model, i.e., a traditional subscription-based journal in which selected articles are published as "open access." Some of these journals deposit only the open access articles in PMC. This agreement also may be used for other sets of articles that are more limited than those covered by a full participation or NIH portfolio agreement.

    • Submitting Citations to PubMed and CrossRef

    If a publisher wishes, PMC will submit citations to PubMed and/or CrossRef on behalf of a journal. In either case, a citation will be sent automatically on the day that an article becomes available on the PMC public site. Citations usually appear in PubMed the day after they are submitted. PMC will use the publisher's account for CrossRef submissions, because PMC does not have its own CrossRef account.


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Last updated: December 11, 2008