Federal Reserve bank notes redeemed by the Treasurer of the United States under section 121a of this title shall be charged against the balance of deposits for the retirement of Federal Reserve bank notes under the provisions of sections 122 and 445  of this title; and charges for Federal Reserve notes redeemed by the Treasurer of the United States under section 121a of this title shall be apportioned among the twelve Federal Reserve banks as determined by the Board of Governors of the Federal Reserve System.
12 U.S. Code § 122a. Redeemed notes of unidentifiable issue; funds charged against
1966—Pub. L. 89–427 substituted provisions allowing the Board of Governors of the Federal Reserve System to determine the proper apportioning between the Federal Reserve banks of the charges for the redemption by the Treasurer of the United States of Federal Reserve notes that are unidentifiable as to bank of issue for provisions that set out the exact formula for determining the proper apportioning of charges using a proportion based upon the amount of Federal Reserve notes of each Federal Reserve bank in circulation in the 31st day of December of the year preceding the date of redemption, with the amount apportioned under the formula charged by the Treasurer of the United States against deposit in the gold-redemption fund made by the bank or its Federal Reserve agent.
 See References in Text note below.