31 CFR § 357.27 - Reinvestment.
(a)General. Upon the request of an owner, the redemption proceeds of a security may be reinvested at maturity in a new security in the same form of registration, provided a new security is then being offered by the Department and provision for reinvestment is made in the offering. The new security must be in an authorized denominational amount and will be issued in accordance with the terms of the offering. If the new security is issued at a premium or with accrued interest, an additional payment will be required from the investor. If the new security is issued at a discount, the difference will be remitted to the owner.
(b)Treasury bills. A request by an owner for a single or successive reinvestment of a Treasury bill must be made in accordance with the terms prescribed on the tender form submitted at the time of purchase of the original bill, or by a subsequent transaction request received not less than ten (10) business days prior to the maturity date of the bill. A request to revoke a direction to reinvest the proceeds of a bill must be received by the Department not less than ten (10) business days prior to the maturity date of the bill. If either a request for reinvestment or revocation of a reinvestment request is received less than ten (10) business days prior to maturity of the original bill, the Department may in its discretion act on such request if sufficient time remains for processing.
(c)Issue date not coincidental with maturity date. If the date on which a security matures or is called does not coincide with the issue date of the security being purchased through reinvestment, the Department may, at its option, hold the redemption proceeds in the same form of registration as the maturing or called security, but no interest shall accrue or be paid on such funds.