“…3 In addition, the imputation procedure we used to estimate unauthorized immigrants' Medicare contributions and expenditures may have limitations, which have been described in other papers that have used this method. 11,12,40 However, given the limited availability of reliable data about the legal status of immigrants in large surveys, the imputation method we used appears reasonably reliable. A sensitivity analysis based on the estimated variation in size of the unauthorized population 41 suggests that unauthorized immigrants provided a subsidy of between $33.6 and $36.5 billion between 2000 and 2011.…”