Wisconsin Department of Revenue disagreed with my filed form. Turbo Tax said I was getting about $4000 but I got $400 with a letter explaining that my WRS pension was incorrectly entered as non taxable. I was glad the state caught the "mistake" so I did not have to return the overpayment, but I still don't understand what happened.
By default, TurboTax treats pension income as taxable in Wisconsin, unless (1) you are a non-resident of Wisconsin, or (2) you told TurboTax that this pension was military or railroad retirement benefits, or (3) you indicated in the Wisconsin interview in TurboTax that you were a member of certain retirement systems and you retired from the system prior to 1964. Please see https://www.revenue.wi.gov/Pages/FAQS/pcs-retired.aspx#retr1
These entries (for #2 and #3) are found on a screen in the Wisconsin interview headed "Retirement Benefits Adjustments".
If you find that this does not explain your situation, please post a new question on the AnswerXchange, giving the details (years, TT product, any entries you made relative to this pension).