This chapter advances understanding of collaborative groups’ progress toward productive engagement during joint activity in STEM learning environments. Our research is grounded in our theorizing and measurement of group disciplinary engagement (GDE) as co-negotiated and shared engagement norms contextualized in middle school science and mathematics curricula. We measure GDE along five engagement dimensions: behavioral, socioemotional, collaborative, metacognitive and disciplinary engagement. We examined a temporal pattern identified from our results from a larger data corpus of 28 group observations. This pattern indicated the significant role of disciplinary engagement (DE), group’s efforts to form conceptual connections around disciplinary content and/or use/application of disciplinary practices, for fostering groups’ subsequent collaborative and behavioral engagement. Results indicated DE was initiated when students resolved a disciplinary problem introduced by a curricular task, interacted with classroom technology, or when responding to teacher’s instruction. These initial efforts to form conceptual connections encouraged groups to jointly attend together (behavioral engagement) in knowledge co-construction to elaborate their understanding in a coordinated and collaborative fashion (collaborative engagement). Findings contribute to theory about short duration engagement dynamics and have implications for the design of tasks that initiate, enhance, and sustain group disciplinary engagement.