Indium based III-V compounds are very important technological materials. However, the indium incorporation depends on several phenomena, among them, the influence of indium segregation has been the most studied. In this paper, we show that to predict accurately the energy levels of In based III-V quantum structures, besides the indium segregation, the indium desorption must also be considered. In order to verify this assumption, we consider InGaAs/GaAs quantum wells as a benchmark case, and simulate 48 different quantum wells comparing with photoluminescence results.