H.R. 2596 — Renewable Natural Gas Incentive Act of 2025

This section establishes a renewable natural gas (RNG) fuel credit of $1.00 per gallon (or gasoline gallon equivalent, defined by a Btu content of 124,800) under IRC §6426(l) for RNG—compressed or liquefied gas derived from biomass and produced by a registered party with required certification—sold or used as fuel in motor vehicles, motorboats, or aviation (through Dec. 31, 2035). It provides rules treating qualifying blended RNG (i.e., RNG mixed with other natural gas under contract) as RNG fuel, subject to volume limits; applies existing IRC §6426 rules on registration, denial of double benefits, U.S. production/use requirements, and energy equivalency to the RNG credit; and authorizes payments for the RNG credit under IRC §6427(e) (through Dec. 31, 2035). (As background, IRC §6426 provides excise tax credits for certain renewable and alternative fuels to reduce the effective tax on those fuels; this provision adds RNG to promote its production and use.) It also requires RNG producers to register under IRC §4101(a).