Abstract: Modern enterprises struggle to scale agile practices from the team level to enterprise-wide information systems (IS) portfolio management. This study empirically develops a four-stage IS Portfolio Agility Maturity Model (IS-PfAM2) to identify the maturity stages for agile IS portfolio management capabilities. Using Necessary Condition Analysis (NCA) on survey data from 47 respondents across 22 organizations, we empirically derive boundary conditions for each maturity stage based on nine design principles organized into four clusters: Organizational Context, Value Flow, Information Flow, and Capital Flow. The resulting four maturity stages, labeled as Novice, Reactive, Adaptive, and Dynamic, provide practitioners with a structured framework to assess their current portfolio agility capabilities and identify opportunities for improvement. Our findings reveal that the different design principles activate at varying levels across maturity stages, suggesting multiple pathways to portfolio agility. This research offers a theoretically grounded, empirically developed tool for guiding IS portfolio transformation initiatives in dynamic business environments.