Authors
Authors of accepted manuscripts who are interested in publishing their article as Open Access should confirm their subscription status with their institutional librarian. If their institution has a site license, the author should note the reduced fee ($850) on the PNAS billing forms included with the author proofs.

PNAS and NIH Public Access
PNAS complies with the NIH public access policy and extends access even further. PNAS automatically deposits the final, published version of all its content, regardless of funding, in PubMed Central (PMC) and makes it free at both PMC and PNAS just 6 months after publication.

It is important for authors who wish to deposit a manuscript in PMC to give PMC a release dates of 6 months after print publication in PNAS. Alternatively, for authors who want their work made free at both PMC and PNAS immediately upon online publication, it is important to choose the PNAS "open access" option when the paper is accepted by PNAS, and to give PMC a release date of online publication in PNAS. The open access surcharge is $850 for authors from institutions with a site license/open access membership. Via either route, authors do not need to deposit author manuscripts in PMC because PNAS will automatically deposit the final published version for public release.

Please see our editorial (www.pnas.org/cgi/content/full/102/15/5303) and our copyright agreement (www.pnas.org/misc/copyright.pdf) for details.

Librarians
A number of librarians have told PNAS that they support the Open Access initiative, and we hope that it will provide an incentive for institutions to adopt site licenses, to which we have given added value. Please help us inform authors at your institution about the PNAS Open Access Option and the Site License/Open Access Membership discount. PNAS is a break-even operation and relies on both author fees and subscription fees to cover its operating costs.

The 2008 PNAS site license descriptions and rates are available at http://www.pnas.org/subscriptions.