The article discusses the issues of setting up the import substitution mechanism in procurement and updating the national regime. The importance of the national procurement regime as a mechanism for supporting domestic producers and protecting the country's domestic market is reflected. The study was conducted in a comparative aspect of the previously existing procedure for the application of the national regime and its updated format from 2025. The difficulties in the application of the national regime have been highlighted, which have been overcome by the unification and codification of all rules in the field under study within the framework of a single legal act. The new rules and interactions are summarized in the updated format of the national regime. Attention is focused on changes in the procurement stages related to the national regime. A research position is expressed regarding the relationship between the foundations of the national regime and the optimization of mechanisms for the application of the national regime. The upcoming adaptation of the participants of the contract system to the new rules and conditions is justified, which will require certain efforts from them.