Interprofessional education is vital in equipping students with the competencies and identity needed to become skilled collaborators and lifelong learners. However, the lack of formative assessment tools renders it difficult to scaffold the development of an interprofessional identity (IPI). Therefore, this article reports the design elements and presents the perceptions of medical students involved in the co-construction of the Rubric Interprofessional Identity Development (RIPID). Following a pragmatist approach, a multiperspective 8-step inquiry led to a manual with definitions, illustrative quotes, scoring instructions and exemplars as well as evidence supporting the validity of RIPID. The RIPID is a generic analytic rubric that can be used to assess the extent to which a learner’s IPI is developing across different contexts on the basis of a variety of assignments and by means of multisource feedback. The theoretically supported criteria account for the (meta)cognitive, emotional and social dimensions of interprofessional learning, of which the descriptors are formulated to elicit reflection. Students are convinced that the RIPID can be used for the authentic assessment of their interprofessional development, confirm its suitability for self-assessment, and see merit in the early introduction in an e-portfolio to promote self-regulated learning. Furthermore, the RIPID can be used for the meta-assessment of programs to improve constructive alignment across the curriculum. Further research is needed to empirically test and psychometrically validate the RIPID at a large scale in different health and non-health settings and to determine its use within a programmatic assessment approach to interprofessional learning.