Partnership has emerged as an increasingly popular approach to privatization and government–nonprofit relations generally. While in principle it offers many advantages, there is no consensus on what it means and its practice varies. Following a review of partnership literature, the article refines the partnership concept, developing two definitional dimensions: mutuality and organization identity. Based on these dimensions, partnership is defined on a relative scale and is distinguished from other relationship types: contracting, extension, and co‐optation or gradual absorption. Examples of each are provided. The model enables actors to assess their relative tolerance for partnership approaches, and provides a common language among potential partners. Linking its defining dimensions to partnership's value‐added assists partners to advocate for partnership approaches from an instrumental as well as normative perspective. The model and inter‐organizational relationship matrix can inform continuing theory building and practical experimentation both to refine defining dimensions and indicators of partnership practice, and to enhance responsiveness to partners' expectations of partnership. Copyright © 2002 John Wiley & Sons, Ltd.