For underpayment penalties, what is the minimum tax amount that must be owed?

The minimum tax amount that must be owed for underpayment penalties is $1,000. This threshold is significant because the IRS enforces underpayment penalties when a taxpayer's withholding and estimated tax payments are less than the smaller of 90% of the current year's tax liability or 100% of the previous year's tax liability (110% if the previous year's income exceeds a certain threshold). If a taxpayer's owed tax amount falls below $1,000, they are generally not subject to underpayment penalties, allowing some leeway for smaller tax discrepancies. This concept helps taxpayers understand their liability obligations and avoid unnecessary penalties as they calculate their payments throughout the year.