First, you need to be sure that the basis for the Roth account has been entered. Then, if the distribution is still taxable, you will be given a screen to enter any possible exceptions to the early distribution penalty, including withdrawal due to disability. If 3-Disability doesn't work, try "Exception Applies".
Please feel free to post any additional details or questions in the comment section.
You may find these steps helpful to report the basis of the Roth:
On the top row of the TurboTax online screen, click on Search (or for CD/downloaded TurboTax locate the search box in the upper right corner)
This opens a box where you can type in “Roth ira” (be sure to enter exactly as shown here) and click the magnifying glass (or for CD/downloaded TurboTax, click Find)
The search results will give you an option to “Jump to Roth ira”
Click on the blue “Jump to Roth ira” link
This will bring you to a screen with check boxes to indicate what types of account you had in 2017. Be sure that Roth IRA is checked. Click Continue.
If Traditional IRA is checked or if you have a spouse that had either type of account, the next questions will not pertain to your Roth IRA. Continue through this section until you are asked whether you made any contributions to your Roth IRA for 2017. This is the beginning of the section where you will enter details about your Roth IRA, including the basis.
Continue answering the questions according to your situation. On the screen where you see Let Us Track Your Roth IRA Basis, click Yes.
Then, on the screen titled Enter Prior Year Roth IRA Contributions, this is asking for your total contributions for years prior to 2016 (basis). If your basis exceeds your distribution, then the distribution will not be taxable.
Finish the rest of the follow-up questions about your Roth IRA.
