This study addresses the lack of studies of diversity in post-Soviet higher education systems. It aims to examine institutional diversity in two post-Soviet countries as the result of higher state and market forces in the context of high-participation systems of higher education. The 'enrollment economy' has become the most powerful signal for higher education institutions in both countries. However, in Belarus, the conservative position of both the state and organizations, mitigates the effects of market-driven signals. The study reveals bifurcation as the key process distinguishing Russian higher education from Belarusian. While still in Russia middle-layer HEIs are not capable of changes in sectoral identity locked-in by the Soviet model.