You can not use turbotax to complete and file ONLY a state return. You MUST first complete the federao return. Then, and only then can you purchase the state module. The state module installs as an add-on to the federal program. Without completing your federal return first (weather you file the federal return or not) you can't even start your state return with any assurance it will be accurate.
After you have purchased, downloaded and installed the state module, close the proram and delete the .tax2015 file in the documents/turbotax directory. THen place the .tax2015 file you downloaded into the documents/turbotax directory. WHen you start the program now, you'll be able to open your already filed federal return, go to the state tab and start your state return.
You can purchase TurboTax 2015 at <a rel="nofollow" target="_blank" href="https://turbotax.intuit.com/personal-taxes/past-years-products/">https://turbotax.intuit.com/persona...>
MAKE SURE you are under the correct tab. Otherwise, you will purchase the wrong tax year, and if that happens, you own it.
Also be aware that you can not e-file a prior year return. So you will have to print it, sign it, and mail it to the state. When you print it (by selecting the "print and file" option) an instruction sheet will be printed with it. READ THE INSTRUCTIONS. There will be two sets of instructions. One for the federal return (which you don't need) and the other for the state return.