Embracing new Open Access models that could make publishing simpler for authors, with no costs for them, Karger introduced Subscribe to Open (S2O) in 2023 with Pediatric Neurosurgery and Developmental Neuroscience. In 2025, we will broaden the pilot to include European Addiction Research and Neurodegenerative Diseases. Stay tuned!

Originally established by the publisher Annual Reviews, Subscribe to Open (S2O) is a model that can allow journals to adopt Open Access yet use existing subscription budget and infrastructure – streamlining Open Access publishing, and at no cost for the authors. So far, many journals in the health sciences that provide Open Access have done so through the Gold model, which typically includes a one-off Article Processing Charge (APC). As those costs can be substantial for authors, especially those in parts of the world with fewer financial resources, they can represent a hurdle themselves. So, the mission of S2O is to serve as an alternative to the prevalent OA model that removes all financial barriers for readers and authors and allow for greater visibility and impact of research via Open Access.

Karger first debuted S2O in 2023 in two journals, Pediatric Neurosurgery and Developmental Neuroscience. In addition to these, we are expanding our model to two more in 2025, European Addiction Research and Neurodegenerative Diseases.

How S2O is Taking Off at Karger

S2O is fairly new and the jury is still out on its promise as a sustainable business model for all types of academic journals in the long term. But it is already having a positive impact by putting more knowledge in reach of the public via Open Access. Beth Bayley, Open Science Manager at Karger Publishers, said: “When Subscribe to Open was first introduced, we were eager to try it, as it represented a truly innovative opportunity to build on Open Access. So far, it looks promising, but more time is needed to fully assess its impact. Exploring new Open Access business models requires careful evaluation.”

That journals may shift between Open Access and hybrid some years, depending on the subscription levels reached, is an aspect of the S2O model that is built into the design. The model thus expands the possibilities for journals to achieve the Open Access goal, because it allows journals to continue to cover publishing costs yet aim for Open Access again for the following year. For the Karger journal Pediatric Neurosurgery, not reaching Open Access in the second year is an opportunity to gain valuable insights into how S2O models works. This experience helps us to learn and refine our approach as we observe how S2O develops for this journal. Hopefully, the level of subscriptions will again meet its target, as the goal of S2O is to regain Open Access status.

What does this mean for the future?

For now, we are continuing to support the S2O model also by adding two more journals. However, we remain curious about the outcome at the end of 2025 and the status of all four journals. As we are committed to being ‘open for Open,’ Karger is determined to support researchers, institutions, research funders, and the public in building a future that meets the diverse needs of the academic community – including through Open Access. Enabling not just reading access but also barrier-free publishing for researchers throughout the world is a significant step toward global equity in publishing.