My Friends and I worked for 5 months on an H2B visa from. We have since left the US.

Can we claim the Medicare and Social security tax back?
( If so where on the form do we do this please?)

One of us underpaid federal tax by a lot. What happens if we don't file a 1040NRez and pay up?

One of us I think owes tax. What happens if that is not paid?
Thanks

No, you cannot claim a refund of Medicare and Social Security tax.

Depends on how much is woed. If it's a lot, the IRS can and probably will track you down to your home country. Depending on the country, your government can act as the IRS' agent to collect the tax.

Thanks for the answer. If the amount of federal tax owed is $100 does the person have to file?Can't work it out from the instructions 1040NREZ

Yes, you have to file!