The safe answer is that all US residents must file a tax return, and I ignore the minimal dollar amounts for individuals to file because for entities there is no minimal amount. I assume this is not a disregarded entity for Federal tax purposes. If you don't file a return then the statute of limitations never starts, so if you are still owe the tax return. If up want the liability protection for the LLC, then you should file, although that alone does not destroy your protection, but if you don't walk, talk, and look like a business and otherwise ignore what an LLC is suppose to do, then no one has to recognize the entity either, which might be important in a court house. Note that you can't really say if you have an income tax in the US until you compute the numbers. Note that foreign income taxes may offset your federal income tax. Usually the Foreign tax credit does not offset all the US tax, but you have to grind the numbers.