 In the year 2000, immigrants' healthcare costs comprised 8.5% of total expenditures on medical care in the United States, while undocumented immigrants' costs were estimated to be approximately 1.5%.Lower costs and degrees of medical care usage may be attributable to existing barriers to care, better health outcomes as described by the "healthy immigrant effect," and reluctance to report health problems.Studies indicate that, even if born in the United States, children of non-citizens tend to have poorer health than children of citizens.