The main economic concerns on the welfare provision to immigrants center around the fiscal burden and the “welfare magnet.” This paper analyzes the feasibility of income assistance policies for immigrants taking these two concerns into account. Since feasibility of welfare programs in the US is determined by immigrants’ labor market performance in the US as well as potential impacts on their migration behavior, I build a structural model that incorporates a joint process of the wage assimilation of immigrants and their selective initial/return migration decisions. I estimate the parameters so as to replicate empirical evidence from various datasets that cover Mexican immigrants. Using estimated parameters, I conduct an experiment on the feasibility of income assistance policies for immigrants that does not rely on the tax revenue from the natives. I find that the welfare provision is possible when the enrollment is mandatory, because the large wage gap between the US and Mexico makes workers to optimally stay in the US despite the taxes.