This article examines the co-financing mechanism for projects in the Volga Federal District (VFD), including the old industrial regions (OIRs), as a means of financial security. The sustainability of the co-financing mechanism is underpinned by the development of relevant federal and regional legislation. At the same time, the legally permissible formality of implementing the institution's functions, including in the old industrial regions, is observed. To overcome the formality of co-financing, it is proposed to enshrine in the institutional design the requirement for strict adherence to the rules of the competitive mechanism: the allocation of subsidies from a higher budget exclusively on the basis of a real competitive selection of projects.