As an archive, PMC is designed to provide permanent access to all of its content, even as technology evolves and current digital literature formats potentially become obsolete. NLM believes that the best way to ensure the accessibility and viability of digital material over time is through consistent and active use of the archive. For this reason, free access to all of its journal literature is a core principle of PMC.
Please note, however, that free access does not mean that there is no copyright protection. As described on their copyright page publishers and individual authors continue to hold copyright on the material in PMC and users must abide by the terms defined by the copyright holder.
PMC is a repository for journal literature deposited by participating journals, as well as for author manuscripts that have been submitted in compliance with the public access policies of participating research funding agencies.
PMC is not a publisher and does not publish journal articles itself.