On September 30, 2026, the Infrastructure Investment and Jobs Act — the most significant federal construction funding law in a generation — expires. What happens after that date will depend on whether Congress can accomplish something that, historically, it has failed to do on time: pass a new surface transportation law before the old one runs out.
The stakes are not abstract. The IIJA authorized $1.2 trillion in total infrastructure spending, including $550 billion in new investment above baseline levels. It has funded over 68,000 projects nationwide. As of January 31, 2026, $568 billion has been allocated and $275 billion obligated. But the mechanism that keeps new projects entering the pipeline — annual formula funding allocations, discretionary grant programs, multi-year competitive awards — all depend on reauthorization.
"IIJA authorization ends September 30, 2026. For formula programs, highway, bridge, and transit funding to states continues at IIJA levels through FY2026. After that, these programs fall back to pre-IIJA authorization levels unless Congress passes a new surface transportation reauthorization bill." — Funding Landscape, February 2026
The conventional wisdom in Washington is that Congress will find a way. But analysts at Transportation for America — who have tracked surface transportation reauthorization since 1991 — note that Congress has operated on short-term extensions of expired transportation laws for roughly a third of the time since that year. The last two bills both required multiple extensions before passage.
Several factors make 2026 reauthorization harder than past cycles. The gas tax is projected to bring in $44 billion in 2028. Continuing the federal transportation program at IIJA spending levels would require outlays of more than $102 billion annually — a $58 billion annual deficit that the "advance appropriations" mechanism used in 2021 cannot replicate. The bipartisan coalition that passed the IIJA is also under strain, with the Trump administration having already rescinded over $2.3 billion in IIJA allocations, including nearly $879 million from the NEVI electric vehicle charging program.
The FY2026 spending legislation has already reduced the IIJA's planned commitments. The NEVI EV charging program absorbed the largest cuts: $503.8 million in formula grants, $300 million in competitive grants, and $75 million in joint office funding — a combined loss of approximately $879 million. Core formula programs for highways, bridges, transit, water systems, and broadband have been protected so far, but advocates warn that further rescissions remain possible before September.
Projects already under construction with funding obligated are relatively secure. Projects that have been awarded but not yet fully funded carry more uncertainty. Projects that depend on new discretionary grant programs for their funding are speculative until Congress acts.
For formula programs — the largest category covering highway, bridge, and transit work — expiration without reauthorization means funding levels revert to pre-IIJA baselines: dramatically lower than the current levels that state DOTs and contractors have built their project pipelines around.
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This article is based on reporting from Transportation for America and federal infrastructure funding data. For more information, visit: https://t4america.org/
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