Post-institutionalism is a promising direction in the study of institutions, developing the methodological ideas of critical institutionalism to build an extended institutional approach (in G. Hodgson's terminology). The mission of post-institutionalism is the development of interdisciplinary, complexity-centered methodologies for the analysis of institutions, allowing the development of institutional research beyond the framework of both new and original institutional theories. The article briefly outlines the logic of the creation and origins of the post-institutional theory, provides its methodological features, philosophical foundations, and guidelines for the research program. Post-institutionalists proceed from the fact that the methodological tools of both the new institutional economics and the traditional (“old”) institutionalism are inadequate to the tasks of understanding and explaining the qualitatively complicated institutions of late capitalism. Such institutions are internally heterogeneous, highly fluid, combine different coordinating principles (logics), their functions and boundaries are difficult to identify. The focus of special attention in post-institutional economics is assemblages – institutional systems that combine heterogeneous institutions with irreducible logics. Institutional assemblages are highly adaptive but also functionally redundant and conflict-prone. Bricolage is considered as the main type of institutional change in post-institutionalism, which is understood as the recombinant creation of institutions by a multitude of actors from the elements available in the access to solve current institutional problems. Institutional change agents are not only institutional entrepreneurs, but also institutional “workers”, i. e. ordinary actors in their daily routine. The main function of institutions from the point of view of post-institutionalism is not the minimization of transaction costs, but the creation of transaction value.