Proceedings of the National Academy of Sciences of the United States of America

Proceedings of the National Academy of Sciences of the United States of America (often abbreviated PNAS or PNAS USA) is a peer-reviewed multidisciplinary scientific journal. It is the official journal of the National Academy of Sciences, published since 1915, and publishes original research, scientific reviews, commentaries, and letters. According to Journal Citation Reports, the journal has a 2021 impact factor of 12.779. PNAS is the second most cited scientific journal, with more than 1.9 million cumulative citations from 2008 to 2018. In the mass media, PNAS has been described variously as "prestigious", "sedate", "renowned" and "high impact". PNAS is a delayed open-access journal, with an embargo period of six months that can be bypassed for an author fee (hybrid open access). Since September 2017, open access articles are published under a Creative Commons license. Since January 2019, PNAS has been online-only, although print issues are available on demand. History PNAS was established by the National Academy of Sciences (NAS) in 1914, with its first issue published in 1915. The NAS itself was founded in 1863 as a private institution, but chartered by the United States Congress, with the goal to "investigate, examine, experiment and report upon any subject of science or art." Prior to the inception of PNAS, the National Academy of Sciences published three volumes of organizational transactions, consisting mostly of minutes of meetings and annual reports. For much of the journal's history, PNAS published brief first announcements of Academy members' and associates' contributions to research. In December 1995, PNAS opened submissions to all authors without first needing to be sponsored by an NAS member.