Offer your thoughts or opinion on the input financial query or topic using your financial background.

Do I have to explain the source of *all* income on my taxes?
Well, that's probably not even all of it. If that stranger did his taxes properly, then he already paid about a third of it to the government because wherever he got it from it was income for him and thus it must have been taxed. Now, the remainder is in your hands and yes, according to US law it is now your income and so now you too, must pay about a third of it to the government, and yes you are supposed to explain where it came from. Be careful giving it to somebody else or it'll be taxed yet again. disclaimer: I am not a US citizen