"Withholding" from a retirement account is just like withholding on a W-2 - it is an estimated pre-payment on your tax. Only when you enter the 1099-R, that you will receive in January, for the retirement distribution and all your other income can the actual tax be known. If the mandatory 20% withholding (and all other withholding) is not enough to cover the years total tax, then you will owe more. If too much then the excess will be refunded to you.
The answer is in your final tax return for the year that includes all of your income, all of your deductions and credits, all of your withholding that calculates the final tax or refund. That is what a tax return does.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
