Mo. Rev. Stat. § 173.440: Tax exemptions, bonds — exception.

The bonds and other forms of indebtedness issued under the provisions of this act, the interest thereon, the proceeds received by a holder from the sale thereof to the extent of the holder's cost of acquisition, or proceeds received upon redemption prior to maturity or proceeds received at maturity, and the receipt of such interest and proceeds shall be exempt from taxation in the state of Missouri for all purposes except the state estate tax.