# Roth Conversion Penalty Explained

> Roth conversion in December triggers IRS penalty for income that didn't exist yet. One form fixes it.
- Title: Roth Conversion Penalty Explained · 24/7 Wall St. | Shortify
- Summary: Roth conversion in December triggers IRS penalty for income that didn't exist yet. One form fixes it. File Schedule AI to erase underpayment penalty from…
- Keywords: roth conversion, irs penalty, schedule ai, tax underpayment, estimated tax, retirement income, tax form, phantom income, tax liability, federal tax, Roth, Conversion
- Source: 24/7 Wall St. — https://247wallst.com/personal-finance/2026/09/20/he-converted-120000-to-a-roth-in-december-and-paid-the-tax-in-april-the-irs-charged-an-underpayment-penalty-back-to-the-previous-april-for-income-he-hadnt-earned-yet-one-form-erases-it
- Author: David Beren
- Published: 2026-09-20T19:15:31+00:00
- Read time: 1 min
- Topics: roth conversion, irs penalty, schedule ai, tax underpayment, estimated tax, retirement income, tax form, phantom income, tax liability, federal tax
## Phantom Income Penalty
The IRS charges a penalty for income that didn't exist yet, treating December income as if it existed in April.
## Form 2210 Fixes It
Schedule AI on Form 2210 rewrites the calculation by tracking income through specific dates instead of quarters.
## Why It Happens
Converting $120,000 in December requires paying tax in April, but the IRS assumes income existed in earlier quarters.
## Tax Withholding Alternative
Withholding tax from a separate retirement distribution avoids the penalty by satisfying all quarterly installments.
## Safe Harbor Option
Pay 90% of current year's tax or 100% of prior year's tax to avoid the penalty without annualization.
## Penalty Waiver
The IRS waives the penalty for retirees who reached age 62 or became disabled during the tax year.
## Timing Matters
Converting in December creates the hardest penalty situation, but converting in early quarters avoids it entirely.
## Form 2210 Requirements
Schedule AI must be filed with the return and requires detailed income records by period to work.
## Key takeaway

File Schedule AI to erase underpayment penalty from phantom income