IRS website: Resident aliens must follow the same tax laws as U.

 If you are a resident alien, you must report your worldwide income from all sources, that is, income from both within and outside the United States.

但是有些visa报税时是可以elect non-resident alien的。如果你父母有绿卡，他们必须要报美国税。这和加拿大税不同。但是如果他们是visitor visa, 而且choose not to be resident to file a tax return, 他们就不应该被claimed as a dependent.

FBAR 也是一样的。U.S. persons, which include U.S. citizens, resident aliens, trusts, estates, and domestic entities that have an interest in foreign financial accounts and meet the reporting threshold。可以参见IRS website: http://www.irs.gov/Businesses/Comparison-of-Form-8938-and-FBAR-Requirements