This chapter examines climate policy efforts across eight German states that joined the Under2 Coalition at different timepoints, analyzing founding member Baden-Württemberg, five early joiners (Bavaria, Hesse, North Rhine-Westphalia, Schleswig-Holstein, and Thuringia), and two later joiners (Lower Saxony and Rhineland-Palatinate). Operating within Germany’s concurrent legislation principle that constrains subnational regulatory autonomy, these states demonstrate varied climate policy and leadership trajectories shaped by the federal energy transition (Energiewende), political configurations, and structural conditions. Baden-Württemberg emerges as the most consistent climate leader, exhibiting cognitive, exemplary, structural, and entrepreneurial leadership through early legislative action, a comprehensive set of policy instruments, and sustained ambition before and after co-founding the Under2 Coalition. Early joiners show mixed patterns: North Rhine-Westphalia initially demonstrated strong leadership before changes in government weakened ambition, while Schleswig-Holstein leveraged structural advantages and Bavaria remained a follower despite early membership. Later joiners present contrasting cases, with Rhineland-Palatinate exhibiting unexpected climate leadership and Lower Saxony remaining a follower despite renewable energy advantages. The analysis reveals that Under2 Coalition membership reinforced leadership where favorable state-level conditions existed—particularly Green Party government participation—while having limited impact on laggard states.