You have two options. The best option would be to file for an automatic six month extension of time to file your return and wait until you get the K-3 form to file it. You will see an option for the extension on your home page in TurboTax towards the end of tax season. The second option would be to indicate in TurboTax that you don't have a K-3 form and file your return without it, then go back and amend the return (you can do this for no charge in TurboTax) when you get the K-3 form to see if your tax changed. If your tax does not change, you don't have to file the amended return.