Scope & Methodology
This article examines the 2026 municipal bond market environment for airport issuers using primary sources including the MSRB 2025 Municipal Market Year in Review, SIFMA municipal bond statistics, FMSbonds.com market yields, rating agency reports, and published bond official statements. All figures and spreads are traced to publicly available sources as of March 2026. The research is not exhaustive—airport finance teams may conduct independent analysis and consult qualified advisors before making financing decisions.
Record Issuance, Widened Spreads, and Elevated All-In Borrowing Costs: Three Market Variables Reshaping Airport Debt Service in 2026
The municipal bond market that airport revenue bond issuers are accessing in 2026 differs from 2021–2023 in three measurable ways: issuance volume ($580 billion in 2025 vs. annual averages of $400–$450 billion in prior years), investor composition (shift to ETFs and SMAs), and yield levels (88 basis points above the 10-year average per Eaton Vance, January 2026). Total new-issue volume reached $580 billion in 2025 — a 13% increase over the prior record of approximately $513 billion in 2024 — making it the second consecutive year of record primary market issuance, according to the MSRB 2025 Municipal Market Year in Review. Total new-issue volume of $580 billion in 2025 was the highest on record for calendar years 2020–2025 per MSRB historical data within that range. The investor base has shifted substantially, with muni ETF inflows of $106 billion since 2022 against mutual fund outflows over the same period (MSRB 2025 Year in Review); yields stand 88 basis points above their 10-year average (Eaton Vance, January 2026); and the Alternative Minimum Tax (AMT) spread that defines the all-in cost of tax-exempt airport bond financing has widened from approximately 20 basis points in 2021 to approximately 60–72 basis points as of March 2026.
For airport CFOs and finance directors preparing bonding authorization requests and rate studies, each of these variables affects debt service costs, coverage ratios, and Cost per Enplaned Passenger (CPE) projections: a 10 bps spread widening on a $500 million bond equals approximately $500,000 in annual interest cost; a 90 bps all-in yield increase adds approximately $4.5 million annually to debt service; and a 15% non-aero revenue decline can reduce DSCR below 1.15x covenant minimums. This article quantifies the current environment using SIFMA, MSRB, and market data as of March 2026, analyzes the AMT spread dynamic specific to airport issuers, and identifies the intersections with airport revenue bond credit mechanics including Debt Service Coverage Ratio (DSCR) sensitivity, refunding opportunity analysis, and rate covenant compliance.
Record Issuance for Two Consecutive Years Has Widened Spreads and Raised All-In Borrowing Costs
Municipal bond issuance set a calendar-year record in 2025, with total new-issue volume reaching $580 billion — a 13% increase over the prior record of approximately $513 billion set in 2024, according to the MSRB 2025 Municipal Market Year in Review, published January 2026. MSRB CEO Mark Kim characterized it as "an extraordinary year" and the second consecutive year of record primary market issuance. The SIFMA March 2, 2026, statistics release shows 2026 year-to-date issuance (through February) of $75.6 billion, down 3.2% year-over-year, suggesting a moderate deceleration from the 2025 peak pace but consistent with an annualized rate of approximately $450–$600 billion.
Consensus forecasts for full-year 2026 issuance range from $555 billion (Hilltop Securities, November 2025) to $600 billion (Goldman Sachs Asset Management, December 2025), with the Goldman figure representing the average of underwriter dealer forecasts. The spread in forecasts reflects the tension between elevated infrastructure-driven new-money supply and a slower pace of refunding activity relative to the 2024–2025 surge driven by issuers front-running potential tax law changes. Hilltop's November 2025 analysis characterized 2026 as "a year of normalization," projecting approximately $440 billion in new money and $115 billion in refundings.
The consequence of record supply for airport issuers is spread widening in the primary market. PNC's Municipal Market Quarterly Review: Q4 2025 (January 14, 2026) documented that credit spreads widened 5–15 basis points across the investment-grade muni space over full-year 2025 as the market absorbed record supply. BBB-rated credits widened 10–15 basis points; AA-rated credits, which represent most rated airport revenue bonds, widened approximately 5–10 basis points against their three-year averages. Charles Schwab's December 2025 muni outlook noted that AA-rated issuer spreads were 19 basis points above their three-year averages as of late November 2025. For an airport planning a $500 million new-money transaction, a 10 bps spread widening relative to historical levels equates to approximately $500,000 in additional annual interest cost, or approximately $10 million in additional total interest over a 20-year bond.
The current AAA Muni benchmark yield curve, per FMSbonds.com as of March 16, 2026, stands at 2.80% for the 10-year, 4.00% for the 20-year, and 4.35% for the 30-year maturity. The AA-rated tier, which corresponds to the majority of large-hub airport revenue bonds, trades approximately 10–25 basis points above AAA at the same maturities. Eaton Vance's Municipal Bond Market Monitor (January 31, 2026) reported that the Bloomberg Municipal Bond Index yield-to-worst is approximately 88 basis points above its 10-year average across the curve — meaning that, on an absolute basis, airport issuers are borrowing at rates roughly 88 bps higher than the 2011–2021 mean, even as credit quality has improved.
The AMT Spread Has Widened to ~60–72 bps — A Structural Airport-Specific Cost Not Affecting Other Sectors
Airport revenue bonds represent a significant share of the municipal market's AMT-exposed securities. Most airport revenue bonds are classified as Private Activity Bonds (PABs) subject to the Alternative Minimum Tax (AMT) under 26 U.S.C. § 57(a)(5), because airport facilities — whether airfield, terminal, or concourse — primarily serve commercial airline operations, a private activity under IRC § 141(b). Airport bonds qualify as exempt-facility bonds under IRC § 142(a)(1). The PAB classification applies broadly across facility types; the distinction is not between airfield and terminal, but between facilities serving private commercial use versus those serving purely governmental purposes. Nuveen's Muni Monitor: Airports (November 2024) estimated that AMT bonds represent just over half of all outstanding airport bonds. The City of Austin's $229.15 million Airport System Revenue Refunding Bonds, Series 2025 (Official Statement, November 6, 2025), carried an explicit AMT designation, illustrating that large CIP-driven transactions continue to be structured with AMT bonds in 2025.
The legislative risk that dominated airport bond finance conversations through mid-2025 — the potential elimination or curtailment of the municipal bond tax exemption — was resolved by the OBBBA. The One Big Beautiful Bill Act (signed July 4, 2025) preserved the federal tax exemption for all municipal bonds, including both governmental purpose and qualified PABs such as airport bonds, according to Jackson Walker LLP's July 31, 2025, analysis of the enrolled bill text. [NOTE: Public Law number to be verified.] The OBBBA also permanently extended the individual income tax rates and AMT exemption amounts established by the Tax Cuts and Jobs Act (TCJA) of 2017 that were scheduled to expire December 31, 2025. This is favorable for airport bond investors: under TCJA, the number of U.S. taxpayers subject to the individual AMT declined from approximately 5.2 million pre-TCJA to approximately 200,000 post-TCJA (Bernstein Private Wealth Management, May 2023). With the OBBBA permanently locking in TCJA AMT exemption amounts, the effective AMT burden on airport bond interest is structurally reduced compared to pre-2017 law.
Despite reduced AMT incidence, the yield premium that airport AMT bonds carry over non-AMT bonds has widened since 2021, not narrowed. Wealth Management magazine's August 2025 analysis of Bloomberg data showed that the 10-year AMT spread on airport revenue bonds — using Atlanta Hartsfield-Jackson Airport (ATL) 2021 bonds as a benchmark transaction — widened from approximately 20 basis points at the time of issuance to approximately 72 basis points as of July 1, 2025. The Metropolitan Washington Airports Authority (MWAA) June 2025 issuance illustrates current-market pricing: a 2036 AMT bond from that transaction carried a yield of 4.37%, rated Aa3/AA-, against a non-AMT comparable yielding approximately 3.65%–3.75% — a spread of approximately 62–72 basis points. For an investor in the 37% federal bracket plus 3.8% NIIT (40.8% combined), the 4.37% AMT yield translates to a taxable-equivalent yield (TEY) of approximately 7.38% (calculation: 4.37% ÷ (1 – 0.408) = 7.38% at 40.8% combined rate including net investment income tax), compared to a 10-year Treasury at approximately 4.35% as of March 2026.
The wider AMT spread has a direct bearing on airport debt service projections. An airport financing a $1 billion CIP program with 60% AMT bonds (a common structure for mixed airfield/terminal programs, per MSRB 2025 data on airport issuance composition) at a 62 bps AMT premium over non-AMT levels would incur approximately $3.7 million in incremental annual interest on the AMT portion, or approximately $74 million over 20 years. Airport finance teams modeling CIP financing costs in rate studies may wish to use a current-market AMT spread of 60–75 basis points rather than the 20–40 bps spreads that prevailed in 2021–2022.
Tax-Exempt Advance Refunding Remains Prohibited — and That Prohibition Costs Airport Issuers Approximately $62 Million Per Year Nationally
The 2017 TCJA eliminated tax-exempt advance refunding of municipal bonds — the ability to issue new tax-exempt bonds more than 90 days before the call date of outstanding bonds. The OBBBA did not restore tax-exempt advance refunding. DWU Consulting's March 2026 analysis, drawing on Brookings Institution 2023 data and MSRB 2024 data, estimates that the nationwide prohibition costs public issuers approximately $495 million per year in foregone refinancing savings. Applying airports' approximately 12%–15% share of outstanding tax-exempt municipal debt and refunding activity, the airport-sector annual cost is estimated at approximately $62 million nationally (illustrative estimate based on a 12.5% allocation of $495 million; not a surveyed figure).