Peer Community In (PCI) Explained

Peer Community In (PCI) is a nonprofit, scientist-run network that peer reviews preprints and publicly “recommends” the ones that pass review — for free, for everyone involved. There is no author fee, no reviewer payment, and no reader paywall at any step. A PCI recommendation is a short, DOI-bearing, citable article in its own right, and it stands independently of whether the underlying preprint is ever also published in a traditional journal.

For a research administrator, PCI is worth understanding as one of the clearest working examples of “publish, then review” (evaluating a preprint on its own merits, separate from any single journal’s brand) combined with diamond open access (no fee to authors or readers at any stage). It sits alongside Review Commons and eLife’s Reviewed Preprints as part of a broader shift in how preprints get evaluated, but its mechanics and its endpoint are genuinely different from both, as covered below.

What PCI actually is

PCI describes itself as a non-profit scientific organization that creates specific communities of researchers who review and recommend, for free, unpublished preprints. It is encouraged and supported by INRAE (France’s National Research Institute for Agriculture, Food and Environment), but PCI itself is organized as a federation of independent, discipline-specific “thematic PCIs” — PCI Ecology, PCI Evolutionary Biology, PCI Registered Reports, PCI Psychology, PCI Genomics, PCI Neuroscience, PCI Microbiology, and others — each with its own recommenders, managing board oversight, and scope. As of this writing PCI operates 21 such thematic communities, with new ones added periodically as research communities organize around the model.

How the review and recommendation process works

PCI does not host preprints itself. The workflow runs on top of existing preprint servers and repositories:

Deposit. The author posts (or has already posted) the manuscript as a preprint on any public server or open archive — see how preprint servers work for the general mechanics.
Submit to a thematic PCI. The author submits the preprint through the relevant thematic PCI’s own website (e.g. PCI Ecology), typically suggesting one or more recommenders who could handle it.
Recommender-led review. A recommender — an established researcher in the field, acting in a role similar to a handling editor — takes charge of the submission and organizes at least two independent peer reviews.
Revision. Based on the reviews, the author revises the preprint (often through more than one round), updating the version on the original preprint server.
Recommendation. Once the recommender is satisfied the work meets the community’s standards, they write and issue a recommendation, which is then validated by the thematic PCI’s managing board before it is published.

Recommenders and reviewers are unpaid volunteers, consistent with PCI’s overall free-for-everyone model.

What a “PCI recommendation” actually is

A PCI recommendation is not a private referee report — it is a short, signed, public article, typically 300–1,500 words, published on the relevant thematic PCI’s own website. Critically, it is issued its own DOI and is formally citable, independent of whatever happens to the preprint afterward. PCI’s own documentation gives a worked example of the citation format:

Bravo IG (2017) Unmasking the delusive appearance of negative frequency-dependent selection. Peer Community in Evolutionary Biology, 100024.

That structure — recommender, year, recommendation title, thematic-PCI-as-venue, article number — is what makes the recommendation function as a standalone scholarly output, comparable in citability to a journal article, even though no journal has necessarily published anything yet.

Peer Community Journal (PCJ) and what happens after a recommendation

A recommendation is the terminal outcome for authors who want one — it is not a guarantee of, or a prerequisite blocking, further publication. From a recommended preprint, PCI describes three paths:

Peer Community Journal (PCJ) — PCI’s own multidisciplinary, indexed, diamond open-access journal. A recommended preprint can be published in PCJ with no additional round of review, since the PCI recommendation itself stands in for the journal’s peer review.
“PCI-friendly” journals — more than 100 journals that have agreed to accept a PCI recommendation in place of running their own peer review, generally returning an editorial decision quickly (PCI cites around five business days for participating journals) since the review work is already done.
Any other journal — authors remain free to submit to a journal with no PCI relationship, which will treat the manuscript as an ordinary new submission and may or may not take the existing recommendation into account.

This decoupling of evaluation (the recommendation) from publication (wherever, if anywhere, the work is eventually typeset and indexed as a journal article) is the core structural idea behind PCI, and it is what distinguishes “publish, then review” models generally from the traditional “review, then publish” journal pipeline. See diamond open access for how PCJ’s no-fee, no-APC funding model fits the broader diamond OA landscape.

Cost and funding model

PCI and PCJ are free for every user — authors, reviewers, recommenders, and readers — at every stage. There are no article processing charges (APCs), no submission fees, and no subscription or paywall on either recommendations or PCJ articles. PCI funds its operations (server infrastructure, editorial-office staff, governance) through in-kind and monetary support from more than 240 supporting universities, research institutes, libraries, and other organizations, rather than through charges to individual authors or readers — the same institutional-support funding logic that underpins diamond OA publishing more broadly.

PCI Registered Reports

One of PCI’s 21 thematic communities, PCI Registered Reports, applies the same recommender/reviewer process to Registered Reports: study protocols are peer reviewed and can receive an in-principle recommendation before data collection, with a second-stage recommendation once the completed study is reported. It runs independently of any single journal, the same way the rest of PCI does — see how to write a Registered Report and author-list changes between Stage 1 and Stage 2 for the mechanics of the format itself.

How PCI compares to Review Commons and eLife’s Reviewed Preprints

PCI is frequently mentioned alongside Review Commons and eLife’s Reviewed Preprints as part of the same broad “evaluate the preprint, not just the eventual journal article” trend, but the three work differently:

Model	Who reviews	What the output is	Endpoint
Peer Community In	Volunteer recommenders/reviewers within a discipline-specific thematic community	A short, DOI-bearing, citable public recommendation	Recommendation itself is citable; PCJ, a PCI-friendly journal, or any other journal are all optional next steps
Review Commons	A single consolidated round of review coordinated by Review Commons (an EMBO/ASAPbio initiative), across life-science disciplines	A confidential “Refereed Preprint” report package the author controls	Designed to transfer directly into one of a defined set of affiliate journals, avoiding re-review at that journal
eLife Reviewed Preprints	Reviewers invited by eLife editors, within eLife’s own editorial process	Public reviews plus an eLife assessment, published alongside the preprint on eLife’s site	eLife itself no longer issues accept/reject decisions on the article as a journal — the reviewed preprint is the published record

In short: PCI is organized around independent, self-governing subject-matter communities rather than one journal’s editorial office; its recommendation is a freestanding citable output rather than a report package or an in-journal assessment; and it is explicitly agnostic about where (or whether) the work is subsequently typeset as a journal article. It is also distinct from cascading peer review, where a manuscript’s existing reviews are passed between journals within the same publisher after a rejection — PCI has no publisher affiliation and operates on preprints rather than on manuscripts already inside a publisher’s submission system.

Current scale

By PCI’s own published statistics, the network has recommended over 1,000 preprints and logged over 6,000 peer reviews of preprints across its 21 thematic communities, with several hundred articles published in PCJ. These figures grow continuously and should be treated as directional rather than fixed — check peercommunityin.org directly for current counts.

Frequently asked questions

Is a PCI recommendation the same as being published in a journal?

Not exactly. A recommendation is its own citable, DOI-bearing article, but it is not a journal publication by itself. Many authors treat the recommendation as sufficient on its own; others go on to publish the recommended preprint in Peer Community Journal, a PCI-friendly journal, or any other journal.

Does anything about the process cost money?

No. Submission, review, recommendation, and publication in PCJ are all free for authors. Recommenders and reviewers are unpaid volunteers. PCI is funded by institutional supporters, not by author or reader fees.

Can I still submit to a traditional journal after getting a PCI recommendation?

Yes. A recommendation does not obligate the author to publish anywhere specific. It can be taken to Peer Community Journal for immediate publication with no further review, to one of the 100+ “PCI-friendly” journals that accept the recommendation in place of their own peer review, or to any other journal, which will review it as an ordinary new submission.

Is PCI the same as a preprint server’s own screening?

No. Preprint servers typically run a light screening check (completeness, scope, basic ethical checks) before posting, not full peer review — see how preprint servers work. PCI’s recommenders and reviewers, by contrast, conduct a substantive peer review of the science, comparable in rigor to a journal’s own review process.

Do I have to publish in Peer Community Journal to get a PCI recommendation?

No. PCJ is one option among several once a preprint is recommended, not a requirement. The recommendation itself is the core output PCI issues; where (or whether) the work is subsequently formatted as a journal article is left to the author.

Peer Community In (PCI): How Free, Recommendation-Based Preprint Review Works