After you file

In TurboTax Online Premier version, you are able to make changes to underpayment penalties by following these steps: 

• Down the left side of the screen, click on Federal.
• Across the top of the screen, click on Other Tax Situations.
• Under Your uncommon tax situations, scroll down to Additional Tax Payments.
• Click Start/Revisit to the right of Underpayment Penalties.
• The screen Underpayment Penalties will tell you if you are reporting an underpayment penalty.
• Answer the questions until you get to the screen Date of Payment.

Your 2021 Federal 1040 line 38 will report an underpayment penalty.

View the entry at Tax Tools / Tools / View Tax Summary / Preview my 1040.

Form 2210 Instructions state:

Who Must Pay the Underpayment Penalty

In general, you may owe the penalty for 2021 if the total of your withholding and timely estimated tax payments did not equal at least the smaller of:

1. 90% of your 2021 tax, or

2. 100% of your 2020 tax. Your 2020 tax return must cover a 12-month period.

This test is made in Part I of IRS Form 2210 which can be viewed at Tax Tools / Print Center / Print, save or preview this year's return.

The IRS will generally figure your penalty for you and you should not file Form 2210. You can, however, use Form 2210 to figure your penalty if you wish and include the penalty on your return.

There are some situations in which you must file Form 2210, such as to request a waiver.