The SE-T is self-employment taxpayer form. Line 18 is for the amount of money earned between March 27, 2020 and December 31, 2020. The self-employment tax on that portion can be postponed for payment in the following year. You can postpone that portion of your taxes due with no penalties or interest.

You can enter 0 on line 18 if you want to pay all of your taxes this year.

What problem are you having with the 1099-NEC?

The IRS does not open until February 12. They work on forms from most common to least common. See Federal form availability for expected release dates.

@AmyCOk, entering in a 0 seemed to solve that problem. I wonder why it wasn't doing that automatically when I told the software to skip that portion about deferment, as it told me to do if I didn't want to defer.

The 1099-NEC issue is apparently a glitch known by turbotax and being explored. On the worksheet Box 1 it wants to, yet fails to, populate the Link to Schedule C text box on the worksheet. It instructs me to navigate back to the Income & Expenses section of turbotax, then back to the part about my 1099 and make sure all the necessary info is entered. I did that and it still says the same warning every time I try to e-file and will not let me continue.

For anyone already calculated to receive any federal refund, I wanted to share my process with this issue.

After reviewing multiple threads on this problem, I decided to enter an amount into line 18. I took my amount in Line 3, divided by 12 to get a monthly amount, and then multiplied by 9 to get an approximate amount for the time period requested. Once I entered that amount into Line 18 and clicked continue, my federal refund amount increased slightly. I'm not sure why this happened. I don't think its because it's deferring any amount for me because the software already informed me I was not eligible to defer because I was receiving a refund. It has now cleared all the reviews, but I'm still waiting to file to see what all of these threads tell me. 

Update: it now says I'm deferring $30 on my summary, despite clicking NO to deferring. I'm waiting to file until there's a fix for this, as I do not want to defer. 

Your self-employment income may be eligible for a portion of your self-employment tax to be deferred.  See this TurboTax Help.

In TurboTax Online Self-Employed, follow these steps to remove the deferral of self-employment tax. 

• Down the left side of the screen, click on Federal.
• Across the top of the screen, click on Deductions  & credits.
• Under Your tax breaks, scroll down to Self-employment tax deferral.
• Click on Edit/Add to the right of Self-employment tax deferral.
• At the screen Do you want more time to pay your self-employment tax?, click Yes.
• At the screen Let's start by getting your eligible income, this dollar amount will be reported on IRS Form SE line 18.  Leave this dollar amount.
• Click on Continue.
• At the screen Tell us how much you'd like to defer, change the dollar amount to $0.
• Click Continue.
• Click through Federal Review to make sure than the Review issue has been removed.
• At the screen Some of your self-employment taxes may be eligible, click Skip.

Did not work for me.  Didn't give me a choice.  Just said I didn't qualify.