Retirement tax questions

In general, the tax system is supposed to be pay-as-you-go, you are supposed to pay your taxes evenly over the entire year, via withholding or estimated payments.  Paying in full at the end of the year can still result in a penalty for underpayment throughout the year.  Even if all your income is a lump sum paid in December, and you also make a tax payment or withholding in December, you can be assessed an underpayment penalty because the IRS assumes the income was paid to you evenly.  (For example, your 1099-R doesn't specify if a $12,000 IRA withdrawal was paid $1000 per month or $12,000 in December.)

 

When you have a lump sum of income, you can file a form 2210 using the "annualized income method" which is a way of showing the IRS that your income was "lumpy" and you paid the appropriate tax in each quarter for the income you received in that quarter.

 

There are some other rules on penalties, it will depend on your overall income and payments.  We would need more details to explain further.