看来你的担心不是空穴来风，看美国某大学对国际学生的警告：

Can international students use Medicaid and Other Public Benefits?

It is a violation of immigration law for non-immigrants (including F-1, F-2 students and dependents) to accept public assistance. In some cases, accepting such assistance could prevent you from securing a visa abroad or reentering the United States. In some cases, you may be refused medical care and services if you are unable to pay for them.

Do not accept public benefits, such as Medicaid. That has been a consistent message from the Immigration and Naturalization Service and the U.S. Department of State for many years. Now there are even tighter restrictions due to Congress' recent enactment of the Welfare-Reform and Illegal Immigration Reform and Immigrant Responsibility Acts.

更多信息点链接：

http://www.salisbury.edu/health/international.html