If there is an underpayment of estimated taxes, TurboTax will calculate that for you and enter the amount on the Form 1040 Line 38.
Go to this IRS Tax Topic for the underpayment of estimated taxes penalty - https://www.irs.gov/taxtopics/tc306
You can use the TurboTax software to annualize your income and payments using IRS Form 2210, Schedule AI
Click on Federal Taxes (Personal using Home % Business)
Click on Other Tax Situations
Under Additional Tax Payments
On Underpayment Penalties, click the start button
If there is a failure to pay or a failure to file penalty that will be calculated by the IRS after they receive your tax return and tax payment and send you a bill in the mail.
