Following the release of the Nelson Memo by the US Office of Science and Technology Policy in August 2022, all recipients of US federal research funding will be required to make their federally funded scholarly outputs, including scientific data, freely available via public access venues with no delays or embargos by December 31, 2025. In light of the upcoming deadline, there has been an ongoing and intensifying scrutiny of money paid to make scholarly content publicly accessible. As part of our project to investigate “reasonable costs” for public access to United States federally funded research and scientific data, we have developed a synthesis report focused on the multi-model scholarly publication ecosystem that facilitates public access as required by the Nelson Memo. This paper outlines the historical developments that have shaped the current landscape, the key financial (cost and payment) stakeholders in the system, and the models and approaches that have developed in the continued shift to public and open access.