31 CFR 348.2 - Redemption/call/reinvestment.
(a) Redemption by financial agents. The securities may be redeemed prior to maturity by financial agents only under such terms and conditions as set forth in agreements between the financial agents and the Department of the Treasury, Financial Management Service, Washington, DC.
(b) Call by the Treasury. The securities are subject to call before maturity. The Secretary will announce such call by any means the Secretary deems appropriate.
(c) Reinvestment at maturity. The securities shall be automatically redeemed at maturity and the principal amount reinvested in new securities having the same description in all material respects as the ones redeemed, except that the Secretary shall have the authority to modify the rate of interest for the re-issued securities. The securities shall be automatically redeemed and re-invested unless the agent certifies in writing, to the Treasury, Financial Management Service, Washington, DC, that it declines automatic reinvestment within seven calendar days prior to maturity date.