Open Educational Resource (OER) authoring projects demand a high level of organization and planning, ideally as early in the project as possible. A memorandum of understanding (MOU) is a flexible agreement between parties to establish the outcomes, tasks, and timetables of a project. The MOU Template for OER Authoring Projects is intended for use by libraries and prospective OER authors, allowing each partner to think through their objectives, needs, and contributions, in order to reach a shared understanding of expectations. It includes sections to identify parties and their roles, documenting the background and context, defining the authors' and libraries' responsibilities, licensing and copyright, funding, contingencies, accessibility, archiving and preservation, and more. Licensed under CC BY, it is intended to be adapted according to the circumstances of each project.