Form 2210: Underpayment of Estimated Tax by Individuals (2026)
Work out — or reduce — the penalty for underpaying estimated tax.
Form 2210 calculates the underpayment penalty when your quarterly payments fell short. You often do not need to file it: the IRS will compute the penalty and bill you. You file it deliberately when you want to REDUCE the penalty, most commonly by using Schedule AI (the annualized income installment method) to show your income arrived unevenly.
Who files Form 2210
- Anyone who underpaid one or more quarterly installments.
- People whose income was uneven and who want to annualize it.
- Taxpayers requesting a penalty waiver for reasonable cause.
- Farmers and fishers using their special installment rules.
Why filing it can save you money
The default penalty calculation assumes your income arrived evenly across the year, so it treats a fourth-quarter bonus or a summer property sale as if you had earned it from January. Schedule AI lets you match each installment to the income you actually received in that period, which frequently eliminates penalties for the earlier quarters.
That is the main reason to file Form 2210 voluntarily. If your income really was even and you simply underpaid, there is usually nothing to gain — the IRS will compute the same figure and send a bill.
Waivers
The IRS can waive the penalty if the underpayment resulted from a casualty, disaster or other unusual circumstance, or if you retired after 62 or became disabled during the tax year or the year before, and the underpayment was due to reasonable cause rather than willful neglect.
Frequently asked questions
Do I have to file Form 2210?
Usually not. The IRS will calculate the penalty and bill you. File it when you want to reduce the penalty — typically via Schedule AI — or to request a waiver.
What is the annualized income installment method?
It matches each quarterly required payment to the income you actually earned in that period rather than assuming even income. It is on Schedule AI and is the main tool for people with seasonal or lumpy income.
How do I avoid needing this form?
Meet a safe harbor: pre-pay the lesser of 90% of this year's tax or 100% of last year's (110% above the AGI threshold). Our planner sizes those payments.
Sources & verification
Last reviewed July 12, 2026.