"Our records indicate you sponsor a 401(k) plan for the benefit of your employees and you filed a Form 5330 (Return of Excise Taxes Related to Employee Benefit Plans) reporting excise tax under Internal Revenue Code (IRC) section 4971(a). This appears to be in error as 401(k) plans are not subject to the minimum funding requirements and, therefore, would not owe this type of excise tax.... It is important to us that you report the correct amount of excise tax due for transactions involving your retirement plan. Please review your records including the information regarding excise taxes and have someone knowledgeable about your above referenced plan provide the following information."