It depends. The IRS system is a 'pay as you go' system. This means that they want the tax when you earn the income. If you didn't make your estimated tax payments evenly throughout the year then a penalty can and will be calculated for underpayment.
For example, if you made your estimated tax payment at the end of the year then there would be an underpayment penalty for the first three quarters of the year, even if you did receive a refund.
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