A Federal statute (4 U.S.C. § 114) restrains a State’s and political subdivisions’ income taxes on a nonresident’s retirement income.
In the 1980s and early 1990s, several States assessed State income taxes on people who no longer resided or worked in the State. How? ‘The State provided you an exclusion from income when you lived or worked here and made your before-tax § 401(k), § 403(b), or § 457(b) contributions to those tax-deferred retirement plans. The State gets income tax to the extent your retirement payout is attributable to the accumulation from the exclusion we provided you.’
Often, this resulted, whether legally or practically, in “double taxation” because the State in which a retiree resided imposed its tax on retirement income, often with no credit for the working-years State’s income tax.
Congress legislated a Federal supersedure, which applies to amounts received after December 31, 1995.
4 U.S.C. § 114 https://uscode.house.gov/view.xhtml?req=(title:4%20section:114%20edition:prelim)%20OR%20(granuleid:USC-prelim-title4-section114)&f=treesort&edition=prelim&num=0&jumpTo=true.