After entering your 1099-INT (or 1099-DIV), when TurboTax (TT) sees that you have tax exempt interest,
you will be asked which state. You most likely selected OK, telling TT that the interest was not taxable by OK,
Instead, check the box "I earned tax exempt dividends in more than one state". In the drop down menu, select "More than one state"* (at the bottom of the scroll down list) and enter the same dollar amount.
*Most mutual funds will provide a breakdown. Some of the interest may not be taxable by OK. But you usually have to ask for it, or find it on their web site. It's usually so little, that many people don't bother.
