Adding a cost basis to a capital gain

[bookfan]

A municipal bond that I held to maturity was reported by Charles Schwab as having a zero cost basis. I tried to override this on the worksheet, but had an error message that overriding should not be done on the form. It's clearly wrong, but TT is not allowing a change. Any ideas, please?

[KrisD15]

How did you enter the information from the 1099-B?

In Step-by-Step input, if you elect to skip import and enter the information, the input screen has a checkbox available for "The cost basis is incorrect or missing on my 1099-B" 

Check that box and continue

Next screen asks about certain situations

Next screen allows you to change the basis 

[bookfan]

Thanks very much, I imported the 1099 composite from Schwab, unfortunately. I just filed. I will have to amend my return since TT kept seeing my adjustment to cost basis as an error--something about not changing the form due to e-filing. Appreciate your guidance.

[LeticiaF1]

Before you amend make sure that your original return has been fully processed by the IRS.  This means that you have received your refund or that you already paid if you had a balance.  

To amend your return:

1. Log in to your TurboTax account
2. Go to Tax Home
3. On the FAQ's on the right side, select How do I amend my return?
4. The option of Amend Using TurboTax will show, select it.

The program will guide you as you make the changes necessary, you do not need to enter anything other than what you are changing.  

For more information about amended returns see the TurboTax help article below.  Feel free to reach back if you have additional questions.  

How to File an Amended Tax Return with the IRS