As you suspect, Oklahoma does not tax Social Security benefits. However, since you are doing a part-year/nonresident return, TurboTax might have asked you what amount of Social Security benefits you received when you were a resident. Is it possible that you answered a question like that?
See Instructions for line 6: "Social Security Benefits If you were a part-year resident, you must enter the part of the federal taxable amount that was received while you were a resident. Do not enter any amount received during the period you were a nonresident."
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Mark as Best Answer"
