This working paper describes the second version of MIDAS (an acronym for ‘Microsimulation for the Development of Adequacy and Sustainability’), a dynamic population model with dynamic cross-sectional ageing. This model simulates the life spans of individuals in the base dataset, including with their interactions, for the years between 2003 and 2060. It enables to produce, on that period, adequacy assessment of pensions in Belgium that is coherent with the baseline budgetary projections of the 2009 report of the Study Committee for Ageing realized by the Federal Planning Bureau’s semi-aggregated MALTESE model. Indeed, MIDAS aligns its socio-economic and demographic projections and its macro-economic assumptions on the 2009 report of the Study Committee for Ageing. The adequacy of pensions is analysed through the replacement ratio, inequality measures among pensioners and poverty risk indicators of the elderly.