The first part of the article examines the socio-political, state-legal, and criminological prerequisites for the transformation of the penal system in the late 1980s and early 1990s. It analyzes the impact of the systemic crisis of Soviet statehood, disintegration processes, and radical socio-economic changes on the functioning of institutions that carry out criminal punishments. Special attention is given to the characteristics of the institutional instability of the penal system, the loss of its previous ideological and organizational foundations, and the formation of conditions that necessitated its subsequent reform. The work substantiates the chronological framework of the study and reveals the methodological and source-based foundations of the analysis, which creates a scientific basis for reconstructing the legal dynamics of institutional changes during the transition period.