In accordance with the Russian Federal Law No. 350 of January 2019 the retirement age for Russians is increased for men from 60 up to 65 years, for women from 55 up to 60 years that requires implementation of organizational technologies of health-preserving, promotion of life and labor potential of population of late able-bodied age. In this regard, the role of day hospitals (DH) functioning directed at maximal possible prolongation of autonomous life and working capacity of elderly population increases. Besides, DH also presents additional reserve of optimization of medical care costs. The purpose of the study is to elaborate guidelines of improving activities of DH for population of late able-bodied age, for the purpose of preventive hospitalization. The study was organized on the basis of pilot medical organization of the Moscow Oblast, consisted of hospital of 600 beds and day hospital of 120 beds. The methods applied included sociological survey, expert judgment, statistical direct observation. The primary data was obtained from the forms of federal and sectorial statistical monitoring for 2014-2018. The analysis of medical documentation concerning pilot medical organization functioning during the year of the study was applied. The sociological surveys of patients of late able-bodied age (5 years before retirement according to the new legislation - men 60-65 years old, women 55-60 years old) who received treatment in day hospital. The results. The analysis of main indices of round-the-clock functioning in-patient and day hospitals in the Russian Federation in 2014-2018 established trend towards improvement of using hospital beds due to development of day hospital. However, bed capacity of hospitals is used ineffectively and experts assume that more than 1/3 of patients could receive medical care or aftercare in day hospitals. The experimental study of planning hospitalization of patients with chronic diseases at out-patient level demonstrated that 11.5% of population of able-bodied age need planned and preventive hospitalization in day hospital. The cost of treatment of patient with chronic pathology is 2-3 times lower in day hospital than in common hospital at the stage of exacerbation. It is reliable to apply at the out-patient level experience of planning hospitalization of patients with chronic pathology in day hospitals followed by performance control. The organization of functioning of day hospital and common hospital requires particular enhancement, including issues of succession, financing of the DS, the remuneration of medical personnel through effective contract determining interest of physician in early discharge of patient to aftercare in day hospital. The day hospital functioning is to be implemented in 2-3 turns. The day hospital is to be located in detached placement and the departments of base medical institution are to used in fullness. The day hospital is be used more actively for purpose of health preservation of population of late able-bodied age who. This contingent suffers of chronic pathology and is in need of preventive and health-promoting therapy in conditions of day hospital.