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Embargo Period: Definition, Meaning & Examples | CASRAI

An embargo period is the length of time after a journal article is published during which the author's accepted manuscript cannot be made freely available in an open repository under the Green open access route. Publishers impose embargoes to protect subscription revenue during the period when access to the version of record is commercially exclusive. Embargo lengths vary by discipline and journal, but commonly run from six months to two years.

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Why publishers impose embargoes

Publishers argue that embargo periods are necessary to protect the commercial value of subscription access during the window when institutions pay for access to newly published research. By restricting free access to the author's accepted manuscript for a defined period, publishers ensure that institutional subscribers are receiving a service — access to current research — that justifies their subscription fees. Critics argue that since the research is predominantly publicly funded, the period of exclusivity represents a transfer of value from the public good to commercial intermediaries. The embargo model is particularly contested in the context of health research, where delayed access to new findings can have real consequences for clinical practice. Plan S, the open access mandate of the cOAlition S funders, takes the position that embargoes on publicly funded research are incompatible with the public interest and should be eliminated.

How embargo lengths vary by discipline

Embargo periods are not uniform across academic publishing. In STEM fields — particularly biomedical research — major publishers such as Elsevier, Springer Nature, and Wiley commonly impose 6 or 12-month embargoes on accepted manuscripts, with some high-impact journals permitting immediate green open access. In the social sciences, 12-month embargoes are standard. The humanities present a different picture: publishers argue that books and journal articles in humanities fields have a longer commercial life and require longer protection periods, and embargoes of 24 or 36 months are not unusual. UKRI's open access policy, introduced in 2022, sets a maximum embargo of 12 months for journal articles across all disciplines for UKRI-funded research, bringing humanities more closely into alignment with STEM norms. Wellcome Trust, as a cOAlition S member, requires immediate open access with no embargo at all.

The cOAlition S Rights Retention Strategy

The Rights Retention Strategy (RRS), developed by cOAlition S — the consortium of major European research funders behind Plan S — provides a mechanism for researchers to bypass publisher embargoes legally. The strategy works by having the funder modify its grant conditions so that the researcher applies a Creative Commons Attribution (CC BY) licence to the author's accepted manuscript at the point of submission to the journal, before any transfer of rights to the publisher. The CC BY licence, once applied, is irrevocable; the publisher's subsequent licence-to-publish agreement cannot override it. Authors submitting under cOAlition S-funded research include a statement to this effect in their cover letter or submission. Wellcome Trust became the first cOAlition S organisation to implement RRS, from January 2021. The strategy works with any journal, including subscription and hybrid journals.

The UK Scholarly Communications Licence and institutional rights retention

Alongside the cOAlition S RRS, the UK Scholarly Communications Licence (UK-SCL) provides an institution-level mechanism for rights retention. Under the UK-SCL, a university asserts, on behalf of all its researchers, that the institution retains a non-exclusive licence to make each researcher's author-approved manuscript available in an open repository without embargo, under a Creative Commons Attribution Non-Commercial (CC BY-NC) licence. This means that even without funder-specific rights retention requirements, the institutional licence takes precedence over publisher agreements that would otherwise impose an embargo. As of 2024, 49 UK universities have adopted some form of Rights Retention Strategy. Rights retention strategies represent a structural shift: rather than negotiating embargo lengths one journal at a time, they establish a prior legal right to open access that publishers must accommodate.

Key facts

At a glance

Definition: The period after publication during which an accepted manuscript cannot be deposited openly
Typical lengths: 6 or 12 months (STEM), 12-24 months (social sciences), up to 36 months (humanities)
UKRI policy: Maximum 12-month embargo for journal articles from UKRI-funded research (policy from 2022)
cOAlition S position: Embargoes are incompatible with Plan S; Wellcome requires immediate open access
Rights Retention Strategy: Authors apply CC BY to their manuscript at submission, bypassing embargoes
UK-SCL: Institutional CC BY-NC licence adopted by 49+ UK universities enabling open deposit without embargo

Common misconceptions

What people often get wrong

Often heard: The embargo period applies to the final published PDF.

Actually: Embargoes typically apply to the author's accepted manuscript (AAM). The version of record — the typeset, branded PDF — usually remains behind a paywall indefinitely unless the article is published gold open access.

Often heard: Rights retention strategies require publishers' permission.

Actually: The cOAlition S RRS and UK-SCL work by establishing a prior licence that takes legal precedence over any later transfer of rights to the publisher. Publisher permission is not required.

Often heard: All open access mandates require immediate open access.

Actually: Mandates vary considerably. UKRI allows up to 12 months' embargo for journal articles. Only cOAlition S funders including Wellcome require zero embargo (immediate open access).

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