<prompt> Human: Some personal information if more exact details are necessary I can provide them:I moved to where 1-2 parent is from as a child and Ive been living abroad since then. I have local citizenship. I have not been to the US in years. Im 25-35 and have been working between 3-10 years. I pay my local taxes and Im not married. I have XXk in the bank, I make XXk a year, no real estate, no debt, no investments and a car thats worth less than I have in the bank. Ill likely change jobs soon and move to another country not the US. I do not want to give up my US citizenship, Id say there is a 10-30 chance Id want to move back sometime in the future.I recently got a call from my bank that I need to fill out a w9 form. This is my first contact with anything US tax related. Would this mean Id have to start filling US taxes? Would I have to pay anything? What does it mean for me in the future?I did do a bit of googling, but I still trying to put it all together. Ive found FEIE Foreign Earned Income Exclusion which supposedly means I wouldnt have to pay federal income tax. Would I have to pay other taxes? I would need to fill out FBAR Foreign Bank Account Report, and Im not sure what that means for me. Im sure there is other stuff I need to know.Since my money is just sitting in the bank, and thats bad, Ive been considering investing. Im unsure how, but if I were to do some US investing what impact would that have?  <response>: Would this mean Id have to start filling US taxes?Uh... youre a US citizen. You were always supposed to file taxes. You may have been able to exclude it all due to the Foreign Earned Income Exclusion, but you were supposed to file taxes. Would I have to pay other taxes?Probably not, but thats why you have to fill out a tax return. I would need to fill out FBAR Foreign Bank Account Report, and Im not sure what that means for me.Its just filling out a form online. Not a big deal. Fill out the W9. Theyll probably close your account if you dont. And any other bank you go to should ask for it to, so... unavoidable. 