For a rental property S corp owned with siblings, the K-1 has a number in Box 17 with code X, which is for "Unadjusted Basis." Where do I enter this in Turbo Tax?

Enter the numbers from  the K-1 on the K-1 entry sheet exactly as they appear on the K-1 form you received.  TurboTax will take care of transferring the numbers to the appropriate place in the return.

To enter information from Schedule K-1 (1065) in the CD/Download versions of TurboTax, please follow these steps:

1. Click on Federal Taxes > Wages & Income > I'll choose what I work on.
2. Under Business Business Investment and Estate/Trust Income, click on the box next to Schedule K-1.
3. On the Tell Us About Your Schedules K-1 screen.  Click on the Start/Update box next to S corporations (Form 1120S).
   
4. If you have already entered K-1 information, you will see the S Corporation K-1 Summary screen.  Click Add Another K-1 to enter your information  (or click on Edit to continue with the existing form entry).    
5. If you haven't yet started entering K-1 information, continue through the screens, entering the requested information.
6. On the screen, Check Boxes That Have an Amount, make sure you mark the box next to Box 17 info.
7. On the screen, Enter Box 17 Info, enter the Code and Amount for each of the box 17 entries on separate lines.
   
8. A new blank line will generate automatically, if needed.