This chapter evaluates the future trend of coordination between the Asian Infrastructure Investment Bank (AIIB) and the Asian Development Bank (ADB) in ASEAN, based on the institutional, political, and operational circumstances that either generate or facilitate selective coordination. It assesses how the experience of co-financing, alignment of safeguards and procurement, portfolio specialization, and changing infrastructure priorities, especially in sustainability and resilience, generate incentives for further collaboration. Other limitations addressed in the chapter include shareholder geopolitics, strategic signaling, mandate overlap, project pipeline, and institutional visibility competition. The combination of these drivers and frictions, the chapter concludes that cooperation is not going to disappear, but it will continue to be conditional depending on the issue area, country situation, and capacity of both banks to sustain their legitimacy and distinguish their roles, which is why the book as a whole assumes that cooperation will be conditional, not convergent or displacing.