31 CFR § 347.34 - Payment (redemption).
The issuance and redemption of a retirement savings bond is conditioned on an Auto-IRA custodian certifying compliance with these regulations and with any additional program instructions identified by Fiscal Service that pertain to that bond.
(a) Payment upon maturity. Payment of retirement savings bonds will be made to an Auto-IRA custodian upon the custodian's submission of a request for redemption to Fiscal Service. The custodian shall request the redemption of all retirement savings bonds at their respective maturity. The custodian shall request the full or partial redemption of a bond held on behalf of a participant upon the request of the participant or other authorized person entitled to amounts in the IRA. Retirement savings bond redemptions will be rounded to the nearest one cent.
(b) Payment upon call. Final interest on any called bonds will be paid with the principal (amount contributed minus withdrawals taken) at redemption and rounded to the nearest one cent.