How do I report a 1099-NEC for an internship stipend?

Please see this post. It is a lengthy description of how to handle this. Replace the words 1099-MISC with 1099-NEC, since this was a pre-TCJA post.

To highlight the part that applies to you in terms of steps:

If box 7 reports the stipend,(Box 1 1099-NEC) you would have to report it as self-employed income, then enter the same amount as your "business" expense.  This will ensure that form 1099-MISC is reported for matching purposes, but the amount is not taxable as self-employment income.

1.   Federal Taxes

2.   Wages and Income

3. Self-Employment, Select Income and Expenses - follow the interview questions; you would report the stipend as if you own a business; once general questions are answered, you would enter the stipend as an expense (you can create your own description). The end result: form 1099-MISC is reported, but the income is not self-employment income because it shouldn’t be.