Only gradually, scholars began to show interest in party competition at the sub-national level. Yet, we still know very little about how long it takes until a regional government gets into office. To narrow this research gap, we examine the effect of previous government experience between parties at the regional and national levels. Government formation processes are expected to be faster if parties currently govern together—i.e. have inertia—or have previous government experience—i.e. have familiarity—at the regional and/or national level. We test our expectations by relying on a newly compiled, comprehensive dataset about government formation duration in Germany between 1949 and 2020. Our hypotheses are largely supported: parties are faster in forming coalition governments if they have inertia at the regional or national level and if they have national familiarity. Our results have important implications for our understanding of the interplay between the national and sub-national levels.