It's okay if your W-2G (gambling income) statement doesn't have a state tax ID number, or any state information at all printed on it. Unless you have state taxes withheld on the winnings, and as long as the casino is either located in your home state (or in a state with no personal income taxes, like Nevada), then you can safely leave Boxes 13-18 entirely blank in the TurboTax data entry. If these circumstances apply to you, then try leaving those boxes empty in the software, with no state selected from the drop-down menu.
On the other hand, if you had state taxes withheld, or if the casino issuing the W-2G is out-of-state (from your tax perspective) and that state also has an personal income tax system, then try using the federal tax ID number from your W-2G statement as the state ID number, and select the appropriate state from the drop-down menu. That method is described in another recent AnswerXchange post, which is attached to this text below.
Finally, if none of these methods are successful for you, and you still have questions or other data entry issues, then please call us for live help and some additional options. Our telephone lines are open during the busy tax season from 5AM to 9PM (Pacific Time), 7 days a week. During the rest of the year, we are open Monday - Friday, with normal business hours. Here is the link to our main support ticket webpage:
https://support.turbotax.intuit.com/contact/