31 CFR § 352.10
Taxation
July 31, 2023
§ 352.10 Taxation.
The interest paid on Series HH bonds is subject to all taxes imposed under the Internal Revenue Code of 1954, as amended. The bonds are subject to estate, inheritance, gift, or other excise taxes, whether Federal or State, but are exempt from all taxation now or hereafter imposed on the principal or interest by any State or any local taxing authority.