Form 5329 is an attachment to the federal income tax return that must be filed by taxpayers who owe a penalty related to their use of a tax-advantaged retirement savings plan such as an IRA or 401(k) ...

(For help on how to do the math, try an RMD calculator.) Next, file tax form 5329, "Additional Taxes on Qualified Plans (Including IRAs) And Other Tax Favored Accounts." This form can be filed ...