The negative amount does not get entered as a 1099 MISC. From the self-employment entry screen you would select to enter Other Self-Employment Income and then enter the negative amount on that screen along with an explanation (enter the minus sign before the number). See the sample screenshots below.
To be brought to the self-employed income section in TurboTax, take the following steps:
Type
Schedule C in the Search box and then
select the Jump to link. You
may first be asked some general questions about your business. After you answer
them, you’ll be taken to the Let's enter the
income for (your line of work) screen where you can enter this income as
Other self-employed Income.
