Introduction. The article discusses the need to expand the number of currently existing clinical and statistical groups (CSG) in the provision of medical care in inpatient settings according to the profile "narcology", while reimbursing the costs of a medical organization associated with hospitalization for a completed case of treatment with the financing of medical care. Purpose: to analyze the average length of stay of patients in the hospital with different diagnosis codes in the provision of emergency and rehabilitation medical care in the "narcology" profile as one of the components for assessing the need to expand the number of CSG. Materials and methods. The calculation and comparison of the average values of the length of stay of patients in inpatient departments of the state budgetary healthcare institution (GBUZ) Samara Regional Clinical Narcological Dispensary (SOKND) in 2022 were carried out. For the studied quantitative indicators, the average values are calculated: arithmetic mean, representativeness error, standard deviation, median, coefficient of variation. To assess the statistical significance of differences in quantitative variables (treatment days) in two groups with different diagnoses of the International Classification of Diseases (ICD), the Mann–Whitney criterion was used in cases with an asymmetric distribution of data. The conclusion about the normality of the data distribution was made using the Kolmogorov–Smirnov and Shapiro–Wilk criteria. To compare the median values of the duration of treatment in three or more groups, the Kraskel–Wallace criterion was used. Statistical and analytical research methods were used. Results and discussion. In 2022, 4022 hospitalizations were carried out in inpatient departments of the SOKND in connection with the provision of emergency narcological care (KSG No. 1). The average duration of stay was 12.1±0.1 days with its minimum value of 8.3±0.1 days for withdrawal caused by opioid use and a maximum value of 18.8± 0.3 days for alcohol dependence syndrome of the second stage on active aversive treatment. 412 hospitalizations were carried out for the provision of rehabilitation drug treatment (CSG No. 2). The average duration of stay was 21.5±0.7 days with its minimum value of 14.6±1.5 days for drug dependence syndrome and the maximum value of 23.8±0.8 days for alcohol dependence syndrome. Statistically significant differences in the length of stay of patients with different diagnoses were revealed both during their stay in the emergency department and during rehabilitation in inpatient conditions according to the profile "narcology". Conclusions. In the existing system of reimbursement of medical organization costs associated with hospitalization for its final case, there may potentially be risks of early discharge of patients, or an increase in the proportion of patients with relatively short courses of treatment. The results obtained indicate that there are prerequisites for the expansion of CSG in the profile of "narcology", while compensating the expenses of a medical organization for a completed case of hospitalization. At the same time, further assessments of the actual costs of medicines and examination of patients are necessary.