Using the actual withholding method to figure a penalty, the TT sum that my withholding "must equal" is $580 more than the W2s entered. Where is TT getting this sum?

If your income exceeds certain thresholds, you're subject to the Additional Medicare tax of 0.9% on earnings above those thresholds. When your wages exceed $200,000 from a single employer, they're required to withhold this Additional Medicare Tax. This withholding appears in Box 6 of your W-2, not Box 2 (which only shows federal income tax withholding).

If this is the case for you, TurboTax includes both your regular federal income tax withholding (Box 2) and your Additional Medicare Tax withholding when calculating your total federal tax payments for the year. That $580 difference could be Additional Medicare Tax.

If not, we can look at your return and see exactly what you see to  help come to a resolution. The return will be scrubbed and won't include any of your personal details.

If you're using TurboTax Online:

Once you're logged in to your account,

- on the left hand panel, click on Tax Tools and then choose Tools

- on the pop up window, select Share my file with Agent

- you'll see a message saying you'll give us a copy of your tax return. Your personal information will be changed so we can't see any private information.

- click okay and you'll get another message with a token

If you're using TurboTax Desktop:

• Click on Online in the top menu of TurboTax Desktop for Windows
• Select 'Send Tax File to Agent'
• Write down or send an image of your token number and state then place in this issue.
• We can then review your exact scenario for a solution

Please reply to this message with your token so that we can further assist you. Let us know all the states, if any, that are included on the return.