If you think the code is erroneous, you should contact the payer to have a corrected Form 1099-R issued.
Don't change the distribution code on your 1099-R when you're entering it into TurboTax. If the code that you enter for the 1099-R doesn’t match what the IRS has on record for the same 1099-R, this will raise a red flag with the IRS.
