If you are a resident alien or citizen of the United States and your filing status is single, you don't have to pay federal tax if your income is $8750 or less ($5350 + 3400 = 8750). If you are married and filing as married filing jointly, then you don't have to pay for additional 8750. However, you don't have to even file tax return if you income is less than 3400 as a single.