UMass Amherst (UMA) has chosen to invest in myriad models of open content, systems and advocacy organizations for well over a decade. What at first was an experimental approach has become more values-based, considered and collaborative. Consistent with its strategic plan, the Libraries are intentionally allocating and tracking part of their acquisitions budget to open scholarship. In an ecosystem of ever-increasing options, the social sciences and humanities (SSH) disciplines, monographs, and non-author processing charge (APC) funding are all under-represented in the open access market. UMA Libraries were an early supporter of Knowledge Unlatched (KU) as providers of OA monographs in SSH. KU will provide a case study of UMA’s acquisitions investments in open content. Both have evolved as organizations, and in their practices. They will discuss their respective histories with open access, how their business partnership has developed and the factors they consider when approaching project and investment decisions. KU will discuss the growth of KU as an OA organization (including recent changes which have been the subject of debate in social media), and the growth of its relationship with UMA as it reflects a common pattern among KU supporting institutions: from initial skepticism to experimentation to expanded support. The presenters will encourage questions and discussion with attendees.