This legislation, known as the Wildfire Reduction Market Expansion Act of 2026, amends the Clean Air Act to significantly broaden the definition of renewable biomass for the purposes of the renewable fuel standard. The expanded definition now includes various materials generated from forest products manufacturing and wood products manufacturing , such as wood residuals, sawdust, wood chips, and bark, while specifically excluding commonly recycled paper. The bill further incorporates trees, shrubs, and their parts from diverse land types, including non-Federal lands managed under sustainability programs or for long-term timber production, and Federal lands where materials are by-products of management activities, fuel reduction, or ecological restoration. It also covers vegetation from tribal lands and materials collected from defensible spaces around structures or from wildfire risk reduction activities within the wildland-urban interface. The legislation establishes specific certification processes for these materials, ensuring they align with sustainable forest management practices and applicable Federal laws.