The Association of Research Libraries (ARL)/Canadian Association of Research Libraries (CARL) Joint Task Force on Research Data Services (RDS) formed in 2020 with a two-fold purpose: (1) to demonstrate and commit to the roles research libraries have in stewarding research data and as part of institution-wide research support services and (2) to guide the development of resources for the ARL and CARL memberships in advancing their organizations as collaborative partners with respect to research data services in the context of FAIR (findable, accessible, interoperable, and reusable) data principles and the US National Academies’ Open Science by Design framework. Research libraries will be successful in meeting these objectives if they act collectively and are deeply engaged with disciplinary communities. The task force formed three working groups of data practitioners, representing a wealth of expertise, to research the institutional landscape and policy environment in both the US and Canada. This report of the ARL/CARL RDS task force’s working group on partnerships highlights library RDS programs’ work with partners and stakeholders. The report provides a set of tools for libraries to use when assessing their RDS partnerships, including assessing partnerships using a partnership life cycle, defining the continuum of possible partnerships, and creating a catalog. Not all partnerships will last the entirety of a librarian’s career, and having clear parameters for when to continue or sunset a partnership can reduce ambiguity and free up resources. Recognizing the continuum of possible partnerships can provide the framework by which librarians can understand the nature of each group. From cyclical to seasonal to sporadic, understanding the needs of a type of partnership can help libraries frame their understanding and meet a group where they are. Finally, creating a catalog of partnerships can help libraries see the landscape of the organization, as well as areas for growth. This approach also aligns with OCLC’s 2020 report on Social Interoperability in Research Support: Cross-Campus Partnerships and the University Research Enterprise, which highlights the necessity of building and stewarding partnerships. Developing and providing services in a decentralized organization relies on the ability to build trusted relationships. These tools will help libraries achieve sustainable growth that is in concert with their partners, generating robust, clearly aligned initiatives that benefit all parties, their campuses, and their communities.