Treas. Reg. 1.148-9 contains special arbitrage rules for refunding issues. These rules apply for all purposes of section 148 and govern allocations of proceeds, bonds, and investments to determine transferred proceeds, temporary periods, reasonably required reserve or replacement funds, minor portions, and separate issue treatment of certain multipurpose issues.
Treas. Reg. 1.148-9(d) provides the following:
(d) Temporary periods in refundings—(1) In general. Proceeds of a refunding issue may be invested in higher yielding investments under section 148(c) only during the temporary periods described in paragraph (d)(2) of this section.
(2) Types of temporary periods in refundings. The available temporary periods for proceeds of a refunding issue are as follows:
(i) General temporary period for refunding issues. Except as otherwise provided in this paragraph (d)(2), the temporary period for proceeds (other than transferred proceeds) of a refunding issue is the period ending 30 days after the issue date of the refunding issue.
(ii) Temporary periods for current refunding issues—(A) In general. Except as otherwise provided in paragraph (d)(2)(ii)(B) of this section, the temporary period for proceeds (other than transferred proceeds) of a current refunding issue is 90 days.
(B) Temporary period for short-term current refunding issues. The temporary period for proceeds (other than transferred proceeds) of a current refunding issue that has an original term to maturity of 270 days or less may not exceed 30 days. The aggregate temporary periods for proceeds (other than transferred proceeds) of all current refunding issues described in the preceding sentence that are part of the same series of refundings is 90 days. An issue is part of a series of refundings if it finances or refinances the same expenditures for a particular governmental purpose as another issue.
(iii) Temporary periods for transferred proceeds—(A) In general. Except as otherwise provided in paragraph (d)(2)(iii)(B) of this section, each available temporary period for transferred proceeds of a refunding issue begins on the date those amounts become transferred proceeds of the refunding issue and ends on the date that, without regard to the discharge of the prior issue, the available temporary period for those proceeds would have ended had those proceeds remained proceeds of the prior issue.
(B) Termination of initial temporary period for prior issue in an advance refunding. The initial temporary period under § 1.148-2(e) (2) and (3) for the proceeds of a prior issue that is refunded by an advance refunding issue (including transferred proceeds) terminates on the issue date of the advance refunding issue.
(iv) Certain short-term gross proceeds. Except for proceeds of a refunding issue held in a refunding escrow, proceeds otherwise reasonably expected to be used to pay principal or interest on the prior issue, replacement proceeds not held in a bona fide debt service fund, and transferred proceeds, the temporary period for gross proceeds of a refunding issue is the 13-month period beginning on the date of receipt.
Treas. Reg. 1.148-9(g) provides the following:
(g) Certain waivers permitted. On or before the issue date, an issuer may waive the right to invest in higher yielding investments during any temporary period or as part of a reasonably required reserve or replacement fund. At any time, an issuer may waive the right to invest in higher yielding investments as part of a minor portion.
Upon election of the waiver in Treas. Reg. 1.148-9(g), an issuer may blend the investments of the sale proceeds of the Refunding Bonds, the transferred proceeds and the resulting investment proceeds for purposes of computing the rebate and yield reduction payments under I.R.C. 148. The waiver may be helpful in refundings that will give rise to transferred proceeds which are invested at rates higher than the Refunding Bond yield. See PLR 201150026 (September 7, 2011, released December 16, 2011) in which an issuer is granted an extension of the deadline for making the waiver election where the issuer’s refunding bonds gave rise to transferred proceeds that were not discovered until the refunding bonds were issued.
(Note, see 1.148-2(h) for waivers not in connection with refundings.)