As long as you are not a permanenet resident to claim social security and medicare when you get old, all the fed taxes, social security tax and medicare are all free $$ to the us government. but, if you want to work and make living in this country you better pay your taxes. you may get away with anything here, but IRS. they would spend thousands to get hundreds from you, and millions to get thousands from you. Don't mess with uncle sammy. By the way you do not get refunds on SST and MCT only FWT. you claim those after you are 59.5 now and 65 after 2015.