CDs are unlikely to be available within the confines of the OP's 401(k) plan. It is true that they would be reasonably tax-efficient in a taxable account nowadays since they don't pay any interest.nisiprius wrote:…., then one way to shorten duration is to move to bank CDs. I think this makes much more sense than fiddling around with different flavors of bond fund. ....
Usually a 401(k) plan will have a "no-lose principal" option such as a money market fund. In my spouse's 401(k) plan for 2013 the money market fund was the best performing fixed income option.