Bond refinancing works by selling a new bond issue and using the proceeds to retire an existing one on better terms, usually a lower interest rate, looser contract covenants, or a smoother repayment schedule. Whether an issuer can do it, and how, depends on the call provisions written into the original bond contract and on how many days sit between the new issuance and the retirement of the old debt. For municipal issuers, a 2017 federal tax change reshaped the economics and closed off a technique that used to be routine.
Why Issuers Refinance
The most common trigger is a drop in interest rates. An issuer paying a 5% coupon on outstanding bonds who can now borrow at 3.5% captures the spread across the remaining life of the debt. The savings have to clear the transaction costs, but when rates fall far enough, the math is compelling.
Rates aren’t the only reason. Original bond indentures often carry restrictive covenants that cap additional borrowing, require certain financial ratios, or fence off how revenues can be used. Refinancing lets the issuer negotiate a fresh indenture with fewer strings, and for some organizations that flexibility matters as much as the interest savings.
Reshaping the maturity profile is a third motivation. When a large chunk of debt matures on roughly the same date, the issuer faces a concentrated repayment obligation that can strain cash flow or force a rushed refinancing under bad conditions. Replacing it with new bonds carrying staggered maturities spreads those payments out.
What the Call Provision Controls
Whether an issuer can refinance at all is a contract question, not a market question. A call provision gives the issuer the right to redeem bonds before maturity at a specified price. The earliest date it can do so is the optional call date, and until that date arrives, the bonds cannot simply be paid off.
Calling bonds usually costs a premium above par. A bond callable at 102 pays bondholders 102% of face value, so retiring a $100 million issue costs $102 million. That $2 million premium eats into the interest savings the refinancing is meant to produce. The premium typically declines as the bond approaches maturity.
The indenture also sets a notice period, generally 30 to 60 days, that the issuer must give bondholders before the call takes effect.
Make-Whole Calls
Corporate bonds often carry make-whole call provisions instead of, or alongside, fixed call premiums. A make-whole provision sets the redemption price at the present value of all remaining interest and principal payments, discounted at a rate tied to the yield on a comparable U.S. Treasury security plus a fixed spread. The bondholder gets whichever is greater: par or the calculated present value. When rates have fallen a lot, that present value can sit well above par, and many issuers discover that the theoretical savings from lower rates disappear once the make-whole amount is factored in.
Current Refunding Versus Advance Refunding
The timing gap between the new issuance and the retirement of the old bonds is where the transaction picks up a name and different regulatory treatment. Federal tax law draws the line at 90 days. If the old bonds are retired within 90 days of the new issuance, the transaction is a current refunding. If they remain outstanding for more than 90 days, it is an advance refunding.1Office of the Law Revision Counsel. 26 USC 149 – Bonds Must Be Registered To Be Tax Exempt; Other Requirements
Current Refunding
In a current refunding, the issuer sells the new bonds and uses the proceeds to pay off principal, interest, and any call premium on the old bonds within the 90-day window.2Municipal Securities Rulemaking Board. Refundings and Redemption Provisions The old bonds disappear, the new bonds replace them, and debt service at the lower rate begins immediately. This is only possible when the call date has already passed or is about to arrive.
Advance Refunding
Advance refunding lets an issuer lock in today’s rates when the old bonds cannot be called for months or years. The issuer sells new bonds and places the proceeds into an escrow account that buys high-quality securities, almost always U.S. Treasury obligations. Those securities are structured to mature and generate enough cash to cover every remaining payment on the old bonds until the call date, when the escrowed funds retire the old debt.
Both sets of bonds sit outstanding at the same time until the call date arrives. Repayment of the original bondholders is now backed by Treasuries in escrow rather than the issuer’s own creditworthiness, giving those investors strong assurance of payment.
Defeasance and the Escrow
Defeasance is the mechanism that functionally removes the old debt from the issuer’s picture even though the bonds legally remain outstanding until the call date. The concept is direct: if an irrevocable trust holds enough risk-free assets to cover every remaining payment, the issuer has effectively eliminated the obligation.
In a legal defeasance, the trustee formally releases the issuer from the debt. In an in-substance defeasance, the issuer deposits the assets but remains the primary obligor, so if the escrow somehow fell short, the issuer would still owe the difference.
For state and local governments, a separate accounting standard applies. A government that places essentially risk-free assets into an irrevocable trust using existing resources can remove the defeased debt from its balance sheet, provided any future payment on it is remote. It must disclose the outstanding defeased amount in each subsequent reporting period.3Governmental Accounting Standards Board. GASB Statement No 86 – Certain Debt Extinguishment Issues
Arbitrage Restrictions on the Escrow
Federal tax law does not let issuers of tax-exempt bonds profit on the spread between their borrowing rate and the return on the escrow investments. If an issuer borrows tax-exempt at 3% and invests the escrow at 4% in Treasuries, Congress treats that 1% spread as arbitrage. Under Section 148 of the Internal Revenue Code, bonds become taxable “arbitrage bonds” if their proceeds are invested in securities yielding materially more than the bond yield.4Office of the Law Revision Counsel. 26 USC 148 – Arbitrage
For refunding escrows, “materially higher” is defined as just one-thousandth of one percent above the bond yield.5Internal Revenue Service. TEB Phase I – Module M Arbitrage Yield Restriction Overview In practice, the escrow almost always earns less than the issuer pays on the new bonds. That gap is called negative arbitrage, and it’s a real cost of advance refunding. On a large deal with years of escrow, it can consume a meaningful share of the projected interest savings.
The 2017 Change for Municipal Issuers
Before 2018, municipal issuers routinely used tax-exempt advance refunding to lock in rate savings well ahead of a call date. The interest on the new refunding bonds was tax-exempt, so the issuer could borrow cheaply even while carrying two sets of bonds during the escrow period. Section 13532 of the Tax Cuts and Jobs Act of 2017 repealed the authority to issue tax-exempt advance refunding bonds after December 31, 2017.6Internal Revenue Service. Advance Refunding Bond Limitations Under Internal Revenue Code Section 149(d)
The statute now states plainly that nothing in the tax code provides a federal income tax exemption for interest on any bond issued to advance refund another bond.1Office of the Law Revision Counsel. 26 USC 149 – Bonds Must Be Registered To Be Tax Exempt; Other Requirements Municipal advance refunding is still legally possible, but the new bonds must pay taxable interest. That forces the issuer to compete with corporate borrowers for capital at a higher coupon, which often erases the savings that motivated the refinancing.7Public Finance Network. Frequently Asked Questions – Advance Refunding of Municipal Bonds Bills to restore tax-exempt advance refunding have been introduced in multiple congressional sessions but have not been enacted, so any municipal issuer modeling an advance refunding today has to use taxable rates.
Running the Numbers
Refinancing is a capital budgeting decision. The issuer compares the present value of future interest savings against the total cost of executing the transaction. Positive net present value means the refinancing creates value. Negative means the existing bonds are better left in place.
The costs are substantial and have to be counted in full. They include underwriting fees, legal fees for bond counsel and issuer’s counsel, rating agency fees on the new issue, trustee and escrow agent fees, printing and filing costs, and the call premium or make-whole amount paid to retire the old bonds. Advance refundings add negative arbitrage on top of that.
A common industry benchmark holds that the present value of net savings should reach at least 3% to 5% of the refunded principal before the issuer moves. That threshold builds in a margin of safety and accounts for something easy to overlook: refinancing today burns the option to refinance later at potentially even lower rates. An issuer capturing 2% savings now might miss 6% savings two years later if rates keep falling. The call option has value, and using it up for a thin margin is a common mistake.
The discount rate in the net present value calculation is the after-tax cost of debt. Taxable issuers deduct interest expense, so savings have to be measured after tax. Municipal issuers paying tax-exempt rates on both sides of the trade have a cleaner comparison, but a taxable advance refunding on the new-bond side requires careful modeling of the blended cost.
Required Participants and Disclosures
Bond counsel delivers the legal opinion that validates the transaction. For tax-exempt bonds, that opinion addresses whether the bonds are validly authorized and binding, what secures them, and whether the interest qualifies for federal and state income tax exemption. Without an unqualified approving opinion, no underwriter will sell the bonds and no investor will buy them. Bond counsel also confirms that the refunding structure complies with arbitrage restrictions and other federal rules that could retroactively strip the tax exemption.
Under the Dodd-Frank Act, any firm advising a municipal entity on a bond offering must register with the SEC as a municipal advisor and owes the municipality a fiduciary duty.8Securities and Exchange Commission. Final Rule – Registration of Municipal Advisors That standard means the advisor must act in the issuer’s best interest. A firm serving as municipal advisor on a deal cannot also serve as the underwriter for the same issuance, a separation designed to prevent conflicts between selling bonds and advising the issuer on whether to sell them.
Municipal issuers and their underwriters must comply with SEC Rule 15c2-12, which requires ongoing disclosure of specified events. Several events tied to refinancing must be filed to the MSRB’s Electronic Municipal Market Access (EMMA) system within ten business days, including bond calls, defeasances, adverse tax opinions affecting the bonds’ tax-exempt status, and the incurrence of new financial obligations.9eCFR. 17 CFR 240.15c2-12 – Municipal Securities Disclosure Missing those filings can impair the issuer’s access to the market for future borrowings.