topic TT will not accept negative number for 1099B adjustment codes in Get your taxes done using TurboTax

TT will not accept negative number for 1099B adjustment codes

RenderUntoCaesar — Sat, 22 Feb 2025 22:39:35 GMT

I'm using TT Business (Windows) and entering 1099-B data in summary form. There are values in the 1099-B box 1f that reduce the gain as reported on the brokerage statement. After entering the proceeds and cost basis TT gives the option to select "My statement includes adjustment codes as described in Form 8949 instructions", which leads to an entry box titled "Total Adjustments to Gain/(Loss)". This is where I should be able to enter box 1g values, but that box will not accept negative numbers (despite the fact that the Help link says to "enter the adjustment as a positive or negative number"). Without entering a negative number here the reported gain in TT is higher than the 1099-B.

I guess that I could increase the basis to force a correct gain, but that seems crude. Any thoughts here? Is this a bug or am I missing something? Thanks!

Re: TT will not accept negative number for 1099B adjustment codes

DavidD66 — Tue, 04 Mar 2025 18:35:58 GMT

You indicated you are using TurboTax Business. What type of return are you preparing? Partnership - Form 1065, S-Corp - Form 1120-S, Trust or Estate Form 1041. I am trying to recreate the problem, but I'm not having any issues entering an adjustment to cost basis. Including a screenshot of your entry screen would help.

Re: TT will not accept negative number for 1099B adjustment codes

RenderUntoCaesar — Thu, 06 Mar 2025 02:23:27 GMT

Hi David. I'm preparing a trust 1041. Here's a screenshot showing where, after I enter a negative value in the adjustments box, TT tells me that the adjustment value must be equal to or greater than zero, as well as the help dialog that says to enter a "positive or negative" number. This occurs when entering 1099-B in summary form.

Thanks for your help!

Re: TT will not accept negative number for 1099B adjustment codes

user17738467590 — Wed, 18 Mar 2026 15:13:53 GMT

I am having the exact same problem in TT Business. Is there a solution?

Re: TT will not accept negative number for 1099B adjustment codes

DaveF1006 — Fri, 20 Mar 2026 19:56:33 GMT

This workaround is widely used by tax pros when software won’t accept negative adjustments:

If you need a –$500 adjustment, increase the cost basis by $500.
TurboTax then calculates the correct gain/loss without needing a negative entry.
This is acceptable because the IRS only cares that the final adjusted basis and gain/loss are correct, not how the software internally arrived there.

Re: TT will not accept negative number for 1099B adjustment codes

RenderUntoCaesar — Mon, 23 Mar 2026 20:36:07 GMT

Thank you Dave for the reply, and yes this is a viable workaround!

But it begs the question of why TurboTax doesn't fix this problem to allow entry of negative numbers? Clearly it is unintentional (i.e. a bug) since TurboTax's instructions say to enter a positive or negative number.