In regard to above post. Generally speaking: An Overpayment/ Refund does not necessarily mean that an "Underpayment Penalty" is not due. However, based on your making the Four (4) Estimated Tax Payments in both Sufficient Amounts AND On-Time, It's probably like an "Underpayment Penalty" was not due. TurboTax computes the Form 2210, and is a good reference, based on the Withholding (if applicable) and Estimated Taxes (and Dates) you provided earlier in the TT "step-by-step" process. And, if the Form 2210 is still available for viewing in the TT "Forms" tab---- Your can glance at both the Lines 3-9 data, that provides minimal payment information (considering 2018 withholding, but NOT taking into account 2018 Estimated Tax Payments), based on your previous year's (2017) tax due. In addition, the TT Form 2210, this year (2018) has an additional section, "85% Exception Smart Worksheet" that includes BOTH 2018 Withholding AND 2018 Estimated Tax Payments (including 2017 Refund applied tp 2018, if applicable). Both of these may confirm for you whether it appears that an underpayment may be applicable (or, more-likely, inapplicable). Additionally, you might want to review the TT "step-by-step" process and review (without making changes), at: "Other Situations"> Additional Tax Payments> Underpayment Penalties. And TT may have a comment addressing "underpayment penalties". (NOTE: I had a similar situation as your's, in that I overpaid Estimated Taxes, on-time, and was due a Tax Refund; and TT indicated on this section: "You don't owe and underpayment penalty. However, Form 2210 Underpayment of Estimated Tax, must be filed with your return"; and whereby, Line 6 was indicated as "Yes"; and Part II, Box A was "checked" (NOTE: I have two other posts relating to what I had to do to successfully e-file my returns (based on TT Premier, CD-version for Mac OS). (NOTE: Unlike some of the "work-arounds" whereby the 2017 Tax is changed to "zero" to prevent the Form 2210 from being filed: I thought it more-wise (as I was concerned that "changing" tax data could potentially affect and/or carry-over to other aspects of the return) to just go with the figures and pre-filled boxes checked as TurboTax calculated my 2018 Tax Return--- And, also not jeopardizing TurboTax's 100% Accurate Calculations Guarantee" (which might have to be relied on, if future issues arise). Hope this helps!
