With the introduction of quasimarket principles in the mid-1990s, the German social service sector faced several challenges from above (the state), within (the organizations), and outside (new competitors and "players"). Within the social services, considerable differences prevail between subsectors; although all reforms have been oriented at the principle of (quasi)markets, the governance arrangements implemented have been rather divergent across subfields. This article compares the effects of the introduction of quasimarket principles in two subfields with very different governance architectures: youth welfare and old-age care. Basic findings include different degrees and variants of hybridity at the meso-level of local welfare arrangements as well as at the micro-level of the organizations in the field. The analysis shows a considerable effect of different governance regimes on the openness of the subfields to new competitors (profit-oriented and voluntary), the reactions of established third sector organizations (internal reforms and hybridization), and the modes of political steering (with varying degrees of informality and oversight).