<prompt> Human: This is the first year that Ive made more than say, 10,000. My adjusted gross income is 30,069 it was 32569 before deducting student loan interest paid, and after the standard deduction of 5800 and an exemption of 3700 my taxable income becomes 20,569. According to the tax tables this means my tax to the government is 2661.Im pretty sure I claimed 0 on W4, but my W2 tells me I paid 2434.91 in income taxes, and it looks like had I not worked overtime and earned only the total amount of my salary, I would have had to pay 2,279 instead of 2,661. In this case I probably would have received a refund.Has anyone here ever had a similar experience? Id like to know how to prevent this and whether or not it could happen if my W4 withholding is set to 0 or 1.Thanks!Edit: type of loanAnd one more thing: Id like to point out that my state refund is 198 so Ive filed for that first so I can pay off most of the federal debt with the state money instead of out of pocket.  <response>: this explains it pretty well: 