Direct comparison
Public Access vs. Open Access
Public access is a funder deposit mandate (free to read, per NIH/Nelson Memo); open access is a broader model that can include CC-BY reuse rights.
Side-by-side comparison
| Dimension | Public Access | Open Access |
|---|---|---|
| Core definition | Free ability to read a specific federally funded manuscript, after deposit, on a mandated timetable. | A publishing-model / output status: free to read (and often free to reuse), as a general property of the work. |
| Who imposes it | Federal funding agencies, via policy directive (OSTP's Nelson/Holdren memos; agency-specific plans -- NIH, NSF, DOE, etc.) | Publishers, journals, repositories, and funder/institutional OA policies -- defined by BOAI (2002) and Berlin Declaration (2003). |
| What compliance actually requires | Deposit of a specific manuscript version (usually the Author Accepted Manuscript) in a designated repository, by a deadline. | Publication via an OA channel or model (gold, green, diamond, hybrid) -- no single universal deposit requirement. |
| Reuse rights beyond reading | Not guaranteed by the mandate alone -- the deposited manuscript can remain fully copyrighted unless a separate license is required. | Central to the original BOAI definition -- "libre" OA explicitly includes a reuse license (commonly CC-BY); "gratis" OA is read-only, the overlap point with public access. |
| Embargo / timing | Historically up to 12 months; the 2022 Nelson Memo directed federal agencies to zero embargo, effective by end of 2025 (NIH accelerated to July 1, 2025). | No embargo by definition for gold/diamond OA; green (self-archived) OA can carry a publisher-set embargo, independent of any funder mandate. |
| Where the output lives | A designated federal repository -- PubMed Central (NIH), NSF-PAR (NSF), OSTI (DOE), etc. | The journal's own site (gold/hybrid), an institutional or subject repository (green), or a no-fee journal (diamond). |
| Cost model | No fee tied to the mandate itself -- it is a deposit/administrative obligation, not a payment. | Often tied to an Article Processing Charge for gold/hybrid; diamond OA has no reader or author fee; green OA self-archiving is free. |
| Governing framework | OSTP memoranda (2013 Holdren Memo, superseded by the 2022 Nelson Memo) plus individual agency public access plans. | Budapest Open Access Initiative (2002) definition, plus publisher and journal OA policies and licensing choices. |
| Scope | Tied to a specific grant or contract -- a condition of the federal award. | A publishing choice, applicable regardless of funding source, and can be voluntary or separately required by a funder/institution. |
| Overlap point | A zero-embargo compliant deposit is "gratis" open access in Suber/Harnad's terminology -- free to read, not automatically licensed for reuse. | "Libre" OA (e.g. CC-BY gold OA) also satisfies most funders' public-access reading requirements, since free-to-read is a subset of what a CC-BY license guarantees. |
Common questions
FAQ
Is the NIH Public Access Policy the same thing as open access?+
No. It is a public-access deposit mandate: it requires a manuscript to be deposited in PubMed Central and made free to read on a set timetable, but it does not by itself require a CC-BY or other reuse license. An author can be fully compliant with the NIH Public Access Policy while the manuscript remains under standard copyright.
Can something be public access without being open access?+
In the strict "libre" sense, yes -- a public-access-compliant deposit that carries no reuse license is not libre open access, even though it is free to read (gratis open access, in Peter Suber and Stevan Harnad's widely used terminology).
Can something be open access without satisfying a public access mandate?+
Yes. A gold open-access article published under CC-BY is open access by any definition, but it only satisfies a specific funder's public access mandate if it is also deposited in that funder's designated repository (or covered by a qualifying transformative agreement) within the required timeframe. OA publication and mandate compliance are separate steps.
Does the Nelson Memo require open access publishing?+
No. It requires public access -- free reading with no embargo -- to federally funded manuscripts (and underlying data), but it does not mandate a specific publishing venue or reuse license. Agencies and individual funders can add licensing requirements on top of it, but the memo itself does not.
Is the Nelson Memo still in effect?+
As of mid-2026, public reporting indicates OSTP is in the process of reconsidering or repealing the Nelson Memo, corroborated by congressional appropriations committee language requesting a briefing on that process; it had not been reported as formally repealed as of that reporting. Confirm current requirements directly against agency policy pages (nih.gov, nsf.gov) rather than treating the original 2025 zero-embargo timeline as permanently fixed.
