Penn State's open access policy, AC02, officially requires you to provide a copy of your accepted manuscript to the Libraries even if your article is already open access, but the Libraries will check for an open access version of your article before asking for one.

The Researcher Metadata Database uses Open Access Button to identify open access versions of scholarly articles. Open Access Button searches a variety of sources, including the Unpaywall database. Ensuring that the repository or publication you choose is listed in Unpaywall's data sources will help ensure that we find the open access version of your article. You can enter your article's DOI into Open Access Button to see what open access versions of your article Unpaywall can find.

• If Unpaywall only finds a preprint, please update it to the accepted manuscript or deposit your accepted manuscript with the Libraries.
• If Unpaywall finds the accepted manuscript or final version of your article, you need not deposit it with the Libraries, and the Researcher Metadata Database will not ask for a copy. It can take some time for our system to discover the article, but once it does, it will be marked as open access based on the Unpaywall database.

With questions about the open access policy, please contact the Libraries' Office of Scholarly Communications and Copyright.