You can enter the 1099-r as printed then make a negative Sch 1 line 21 entry for the amount not taxable which will negate the earlier entered amount ... you will still need to mail in the return with the explanation attached.
• Click the Federal Taxes tab ( Personal in the Home & Business version)
• Click Wages & Income. (Personal income in the H & B version)
• On the screen "Your 2018 Income Summary," scroll all the way down to the last section, "Less Common Income."
• Click the Start or Update button for the last topic, "Miscellaneous Income, 1099-A, 1099-C."
• On the next screen, "Let's Work on Any Miscellaneous Income," scroll down and click the Start or Update button for the last topic, "Other reportable income."
• The next screen asks, "Did you receive any other taxable income." Click Yes.
• On the next screen, "Other Taxable Income," enter a description and the amount. Click Continue.
• On the next screen click Done.
The income will be reported on Form 1040 line 21 with the description that you entered.
