Interdisciplinary (ID) collaboration is often evaluated by outcomes such as grants and publications, which are regarded as primary indicators of success (Reinholz & Andrews, 2020). Yet effective ID collaboration relies on commitment, collegiality, consensus, continuity, and communication (Pelaez et al., 2018). As such, we currently have an incomplete understanding of what shapes successful ID research collaborations. Using the Community of Practice (CoP) framework (Lave & Wenger, 1991), this study aims to answer the central question: How do members’ perceived value of collaboration, experienced challenges, institutional policies, and activities shape the formation of collaborative networks and the advancement of research integration in a BII?

We examined the evolution of ID collaboration within a Biology Integration Institute (BII) using a longitudinal mixed-methods approach integrating social network analysis (SNA), semi-structured interviews, and multi-year document analysis to characterize collaboration over time. The evolution of collaboration networks aligns with the Socio-Cognitive Framework of Research Integration (Rossini & Porter, 1979) and CoP developmental stages, illustrating how integration advances alongside community maturation.

Findings reveal staged network development aligned with CoP phases: potential, coalescing, active, stewardship, and transformation. During the potential and coalescing stages, collaboration is primarily leader-driven, with the institute director serving as the central initiator. In the active stage, faculty across disciplines negotiate expertise, co-develop shared models, and produce joint research outputs. However, progressing to the final stages of integration, where shared group knowledge forms, requires integrators. Integrators act as connectors across disciplinary domains and expert groups, facilitating knowledge negotiation and collective learning, as reflected in the stewardship stage, where integration is distributed and collectively sustained rather than leader-driven. The leader acts as an initiator in early phases, faculty serve as facilitators during expansion, and postdoctoral researchers emerge as integrators who bridge disciplinary and relational boundaries. Institutional activities, policies, motivational dynamics, and structural barriers influence these stages and shape the sustainability of ID integration.

While initial funding and leadership vision unified the institute at its inception, the motivation of ID researchers sustained collaboration during the community's transformation stage. Findings from our interviews suggested that, despite the loss of funding due to changes at the federal level, members expressed a strong commitment to continuing collaborations and pursuing new grant opportunities. Nearly all faculty (n = 17) indicated willingness to seek alternative funding sources. Members emphasized that the institute’s primary value lay in convening researchers with aligned interests and collaborative mindsets, enabling meaningful ID partnerships they aimed to sustain. Leadership transitions to early-career postdoctoral researchers (n = 3) created opportunities for ID professional development and expanded leadership capacity.

The work contributes to the science of team science by providing a longitudinal account of how ID collaboration develops and stabilizes within an academic institute. Integration emerges through repeated participation, structured activities, and the work of integrators who bridge disciplinary and relational divides. Sustained collaboration requires institutional recognition of relational aspects alongside traditional productivity metrics. Supporting integrators, designing structured cross-boundary interactions, and valuing sustained collaboration as an outcome are critical for building an ID CoP.