Income is the money you made at work. You should get a W2 from your employer. If you get a 1099 you should also be able to see how much you made. It is also the interest you made off your savings account or cd's. It can be a gift. Not ten bucks from your brother but a substantial gift. It can be an inheritance. That is all I can think of right now. Oh, it was and I think it still is that you have to count income from any source if it is over six hundred dollars. If under you should but don't have to. Maybe someone else knows the exact amount.