I was living in Portland last year and had a TN work visa (I am from Mexico City) but decided to come back home. The company I was working for decided they wanted to keep working with me but as a freelancer. Since I already had a US bank  account, I am getting paid there. I am given the form 1099 to file my taxes. Do you know what percentage of what I am earning is what needs to be paid to the IRS?

Am I allowed to do this, even if Im not living in PDX anymore? Not sure if my Social Security Number is still valid if Im no longer a resident.