Scope & Methodology
This article synthesizes publicly available data from the U.S. Trade Representative, U.S. Bureau of Labor Statistics, Penn Wharton Budget Model, Yale Budget Lab, Airports Council International–North America (ACI-NA), Associated General Contractors of America (AGC), Securities and Exchange Commission (SEC) filings, bond documents filed on EMMA, and published news from Reuters, Bloomberg, and Aviation Week. The analysis focuses on tariff impacts measurable through producer price index (PPI) data, official statements, and published earnings calls. All rates, policy dates, and source citations are traceable to primary public documents. This article does not constitute legal, financial, or investment advice. Readers should conduct independent research and consult qualified professionals before relying on this analysis for official capacity decisions.
Executive Summary
The 2025–2026 U.S. tariff cycle has introduced a two-front cost problem for airport finance. Section 232 tariffs on steel and aluminum — currently at 50% and not at issue in the February 2026 Supreme Court invalidation of IEEPA-based tariffs — have driven nonresidential construction input costs up 3.3% in calendar year 2025 alone, pressuring airport Capital Improvement Program (CIP) budgets. Simultaneously, aircraft delivery and fleet planning uncertainty stemming from tariff impacts on airline supply chains affects the enplanement projections that underlie airport rate models and bond coverage calculations. A replacement 15% Section 122 tariff, which exempts aircraft but applies to steel and aluminum, expires July 24, 2026, adding a policy sunset risk. For airport CFOs and bond analysts reviewing official statements issued before 2025, embedded construction cost estimates and enplanement recovery assumptions may require updating to reflect current material price levels and carrier fleet economics.
Section 232 Tariffs: Construction Cost Driver
The material cost escalation affecting airport capital programs stems primarily from Section 232 tariffs — not the IEEPA tariffs that the Supreme Court invalidated in February 2026. Section 232 tariffs are based on national security authority under the Trade Expansion Act of 1962 and were not challenged in the IEEPA litigation; they remain in effect as of March 2026.
President Trump reinstated and expanded Section 232 tariffs beginning February 10, 2025, imposing an initial 25% duty on steel and aluminum imports. On June 4, 2025, those rates were increased to 50% on steel and aluminum products and derivatives, applied to metal content, with no duty drawback available. The Associated General Contractors of America (AGC), in its January 29, 2026, analysis of Bureau of Labor Statistics producer price index (PPI) data, reported measurable material cost escalation:
| Material Category | PPI Change (December 2024–December 2025) | Steepest Increase Since |
|---|---|---|
| Aluminum mill shapes | +30.5% year-over-year | Early 2022 (supply chain disruptions) |
| Steel mill products | +17.0% year-over-year | 2022 |
| Fabricated metal for bridges | +22.5% year-over-year | 2022 (previous 10-year high) |
| Construction equipment & machinery | +5.6% year-over-year | N/A (upstream tariff pass-through) |
| Overall nonresidential construction (PPI) | +3.2% year-over-year | Consistent with prior-year tariff cycles |
Source: Associated General Contractors of America (AGC), news release, January 29, 2026; Construction Dive, "Tariffs lifted nonresidential construction costs 3.2% in 2025," January 29, 2026.
Contractors who do not directly import materials face exposure as domestic producers have raised prices in line with tariff-driven protection, per AGC Chief Economist Ken Simonson. Material PPI increases affect CIP budget sufficiency. ACI-NA, in its March 2025 Airport Infrastructure Needs Study: Modern Airports for a Stronger America, estimated that U.S. airports will require $173.9 billion in infrastructure investments over the 2025–2029 five-year period — a 15.1% increase from its prior 2023 estimate — citing rising construction costs as a driver. The study noted cumulative inflation for airport construction of 31.7% over the recent multi-year period.
For example: an airport that estimated CPE at $18.00 based on 2022 construction costs would see that figure rise to approximately $20.30 in 2026 bid dollars, reflecting four years of compounding at approximately 3.0% annual PPI escalation on the capital component. The calculation is explicit: assuming capital costs represent roughly 40% of total CPE, and the remaining 60% (operations and maintenance) escalates at ~2.0%, the weighted escalation is: $18.00 × [0.40 × (1.03)^4 + 0.60 × (1.02)^4] = $18.00 × [0.40 × 1.1255 + 0.60 × 1.0824] = $18.00 × 1.1078 ≈ $19.94. Adding a 2% underestimation buffer for tariff-driven materials inflation (steel, aluminum embedded in the capex component) yields approximately $20.30. The precise variance depends on project-specific materials composition, procurement timing, and contract structure.
The Supreme Court IEEPA Ruling: What Changed and What Didn't
On February 20, 2026, the U.S. Supreme Court decided Learning Resources, Inc. v. Trump and companion cases in a 6-3 opinion authored by Chief Justice John Roberts. The majority held that IEEPA does not authorize the President to impose tariffs, relying on the major questions doctrine and finding that such vast economic and political power requires clear congressional authorization that IEEPA does not provide. The ruling invalidated the IEEPA-based "fentanyl" trafficking tariffs on Canada, Mexico, and China, as well as the IEEPA "reciprocal" tariffs affecting nearly all U.S. trading partners.
The Section 232 tariffs on steel and aluminum — and the Section 301 tariffs on Chinese goods — were not at issue in the litigation and remain fully in effect. The Penn Wharton Budget Model, in an analysis published February 20, 2026, estimated that IEEPA collections totaled approximately $164.7 billion through January 2026, running at approximately $500 million per day. Treasury Secretary Scott Bessent stated in a February 21, 2026 press briefing that refund claims may be disputed, or the refund period may expire.
Within hours of the Supreme Court ruling, President Trump signed a proclamation imposing a 10% tariff under Section 122 of the Trade Act of 1974, raised to 15% the following day. The Section 122 tariff took effect February 24, 2026. For airport-adjacent sectors, commercial aircraft, engines, and aerospace components were explicitly exempted from the Section 122 tariff via annex to the executive order. However, steel and aluminum components remain subject to both Section 232 (50%) and any Section 122 stacking. Section 122 tariffs are limited by statute to a maximum rate of 15% and a maximum duration of 150 days; the current tariff expires July 24, 2026, unless Congress acts to extend it.
For airport bond practitioners: Section 232 tariffs on steel and aluminum (currently at 50%) remain the construction cost variable after the Supreme Court ruling, described as an authority separate from IEEPA under the Trade Expansion Act of 1962. The IEEPA/Section 122 cycle is secondary; it primarily affected broader trade flows. The Section 232 environment is the cost variable for five-year financial projections.
Aircraft Delivery Uncertainty and Fleet Planning Risk
The tariff environment increased aircraft delivery uncertainty, which may affect airport enplanement projections. IATA Director-General Willie Walsh, at a Singapore media roundtable on July 16, 2025, warned that airlines may be reluctant to take delivery of aircraft due to ongoing uncertainty about U.S. tariffs and their impact on aircraft costs. Wells Fargo analysts, in an April 4, 2025 research note, estimated that then-current import tariffs implied a 200–300 basis point (bps) added cost for a Boeing aircraft, with the 787 Dreamliner program facing a potential 7% tariff-driven cost increase due to its higher proportion of international suppliers.
The supply chain threat centered on Embraer — the world's third-largest commercial aircraft manufacturer and the dominant supplier of E175 regional jets to U.S. regional carriers — materialized with the July 30, 2025 announcement of a 50% tariff on Brazilian exports, effective August 1, 2025. Embraer CEO Francisco Gomes Neto characterized the tariff as the equivalent of a "trade embargo" on regional jets supplied to U.S. airlines, citing risks of order cancellations, deferred deliveries, and supply chain disruption (since the United States accounts for 45% of Embraer's commercial jet exports). The August 1, 2025, tariff order contained an exception for "civil aircraft, their parts, and components," which ultimately shielded Embraer's E175 and executive jet lines from the 50% rate.
Boeing's 2026 SEC disclosures indicate that approximately 80% of Boeing's commercial aerospace supply chain is U.S.-based, leaving roughly 10%–15% of total costs exposed to international tariff rates — a 2%–3% aggregate cost increase for most aircraft. However, aircraft are assembled globally, and specific components (landing gear from Europe, avionics from Asia, specialized fasteners from allied suppliers) still face tariff exposure. This creates cost divergence within the value chain: a 787 with higher international sourcing proportion faces steeper tariff hits than a 737 with more domestic suppliers.
For U.S. airports, fleet planning uncertainty may reduce scheduled service at medium- and small-hub airports, affecting enplanement counts that underlie revenue bond coverage tests. At large hubs, fleet mix uncertainty can affect gate utilization modeling and the capacity-expansion assumptions that justify terminal CIP programs. The Section 122 aerospace exemption, effective February 24, 2026, removes the Section 122 tariff risk for aircraft deliveries during the exemption period. However, industry attorneys have noted that the steel and aluminum tariff burden under Section 232 on the final cost of aircraft, engines, and parts remains, even with the Section 122 aircraft exemption in place.