AGB stars are ideal IR targets because they are cool and bright. Mostof them escaped detection in optical or shallow IR surveys in theeighties contributing to the puzzling missing number of AGB stars withrespect to theoretical predictions and former stages ofevolution. Observations and AGB models have advanced steadily in thefollowing decades providing us with an almost complete view of the AGBstars in the Magellanic Clouds. Their properties are tracers ofstructure and chemistry across galaxies. New surveys will be able tofill-in the gaps, in terms of sensitivity and monitoring, providingnew constraints for the formation and evolution of the MagellanicClouds.