Partly as a consequence of the Great Recession, the German party system is being transformed. The eurozone crisis, albeit not impacting negatively on the German economy, helped produce a populist far right-wing eurosceptical party as a new political force, the Alternative für Deutschland, confirming a growing fragmentation of the party system. The entry of this party into the Bundestag after the 2017 legislative elections is evidence of increased electoral volatility and ideological polarization, and suggests a transformation of the party system from a fluid five-party system to a fluid six-party system. The chapter analyzes the systemic characteristics of the German party system and maps the changes in the party system structure. It argues that the beginning of a process of party system de-institutionalization is observable, by which the patterns of interactions between political parties have become more unpredictable and unstable.