The paper deals with how a developing country like Iran can prevent socio-economic impacts of demographic and disability transition. This period started between 1991 and 1996 with a rapid decline of fertility and mortality rates and still continues today. This demographic stage constitutes the window or bonus of the best opportunity for Iranian policy makers to do their plan for rapid aging of population. So we developed DOPAMID as the first dynamic projection model from socio-demographic indicators such as fertility rate, mortality rate, sex and age and marriage date of Iranian people. DOPAMID is able to show the evolution of the numbers of dependent aged people. New theories about aging of population describe the importance of disability transition as well as health and demographic ones. So we carry out this study to know when disability transition happens in Iran, how many frail people will live in future and how many family and/or sociomedical carers they will need for ensuring a good quality of life.