I don't think your IPERS contributions have any effect on your tax return. They are pre-tax contributions for both federal and state, so the amount of your IPERS contributions is already excluded from box 1 of your W-2. You don't get any additional deduction for it on your tax return. Any indication in box 14 of your W-2 regarding your IPERS contributions would just be for your own personal information (although you should still enter it into TurboTax as Steam_Train indicated).
