I assume you are asking about an pre-tax IRA, namely the contributions were made with before tax dollars. Normally, changing an annuitant to your current spouse will not be taxable...but the Insurance Company who issued this contract, will be the one to determine if it is permitted. Provided the funds stay in the IRA and they continue to accumulate, there is not tax liabilty created. But once you start annuitizing it, the funds will then be taxable...again, assuming the annuity was funded with pre-tax dollars.
Good Luck to You!!
Kelly C, CPA