Introduction. Next-generation sequencing (NGS) is a molecular approach that can provide clinicians with comprehensive information about a patient’s molecular profile, which is an important aspect of the effective application of targeted therapy.Aim. To assess the frequency of tumor somatic mutations in non-small cell lung cancer (NSCLC) in a cohort of Russian patients to subsequently optimize diagnostics and personalize treatment strategies.Materials and methods. The study included the results of NGS testing from a cohort of 1.400 NSCLC patients between March 17, 2023, and July 22, 2024. Several other clinics across the country participated in this multicenter study. Panels with various options for identifying potential genetic alterations were used. An analysis of the frequency of various alterations was conducted based on the panel used, clinical characteristics of the patients, considering the geographical and ethnographic diversity of the regions in the country.Results. Mutations were most frequently found in the KRAS (17.9%) and EGFR (15.8%) genes, particularly among never-smoker women. The frequency of rare mutations such as RET, MET, and NTRK corresponds to literature data and underscores the need to expand the group of patients being tested for these alterations. However, deletions in exon 19 of EGFR (12.7%) and KRAS G12C (16.4%) were also found among smokers. The results highlight the inadequate scope of existing testing, partly due to the lack of co-mutation assessment and primary resistance mutations, while also demonstrating possible differences when using various diagnostic panels.Conclusion. The implementation of NGS in public health systems allows for a more personalized approach to selecting treatment strategies for patients. The data obtained can be used in predictive models to optimize drug distribution.