Once a municipal bond is refinanced, (prerefunded) the issuer uses the proceeds of the new issue and purchases US Treasury securities (collateral) that are used to pay the interest and principal on the original, more expensive debt until maturity or the call date, whichever the escrow agreement states.

FORBES: Pre-Refunded Munis Are A Bargain

MS. BROWNER: We reached an agreement with BP that they will establish an independent claims facility and an escrow account.

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