Plan S initiative at the National Autonomous University of Mexico

This paper shows how Plan S arises and works, the impact it can have on the subscriptions of the scientific and academic journals of the National Autonomous University of Mexico (UNAM), as well as the first approaches of some publishers who see in this University and Latin America an opportunity to implement this new publication model. The way of publishing has changed due to the use of technologies that have brought with it the emergence of the Open Access (OA) movement derived from the Budapest Open Access initiative proposed by the Open Society Institute in 2001. Plan S is an initiative that arises in 2018 to accelerate the transition to Open Access, which will allow re-search results to have greater visibility and citation. Plan S includes transformative agreements that can be established between publishers and libraries, since it is intended to change the payment for subscription to journals for the Read and Publish model, where the publisher receives a payment to read and a payment to publish in a single contract, while under the Publish & Read model the editor only receives payment for the publication of articles by authors from an institution and the reading of journals is included at no additional cost, precisely at this point, the library plays a relevant role among the initiative and its academic community. Therefore, we agree that Plan S, the cOAlition S initia-tive and the transformative agreements are a great support for open access publishing, since they directly lower the costs of the Article Processing Charges (APC) and offer researchers various options for publish their findings or advances.