The Diesel Price Reduction Act of 2026 prohibits the export of diesel fuel from the United States when domestic prices are elevated. Specifically, the Secretary of Commerce must ban diesel exports once the average retail price of diesel fuel in the United States exceeds $5 per gallon for 14 consecutive days, and this ban remains in place until prices drop below $4.50 per gallon for 30 consecutive days. The legislation is intended to help reduce diesel prices for American consumers and businesses by keeping more fuel supply in the domestic market during price spikes. The bill affects U.S. diesel fuel exporters and trading partners who purchase American diesel, while benefiting domestic consumers and industries that depend on diesel. No specific funding or implementation timeline beyond the price-trigger mechanism is included in the legislation.