In Mississippi retirement distributions are generally nontaxable (SS, IRA, pensions)
457B distributions are deferred income from wages and are taxable by the feds.
I cannot find a definitive statement that my 457B distributions past age 65 are or are not taxable in MS. Somehow I got the impression that they are taxable by TT but an accountant says they are not. The Lincoln W2 I receive assigns them to state wages (and federal of course) and applies the withholding to MS and the feds as well, for what that is worth.