HB 2596 creates a new renewable natural gas (RNG) fuel credit under the Internal Revenue Code. The credit applies to RNG sold or used as fuel in motor vehicles, motorboats, or aviation, and is calculated as $1.00 multiplied by the gallons or gallon equivalents of RNG (including blended RNG) that are placed in service as fuel.
The bill also tightens production and certification pathways, requires RNG to be produced by registered producers, and adds a 2035 sunset. It introduces a domestic production constraint and a certification process to verify product identity and volume, and provides for payment of the credit to sellers or users.
The amendments are paired with related changes to registration, anti-double-benefit rules, and energy-content definitions, and they take effect for fuel sold or used after December 31, 2025.
At a Glance
What It Does
Establishes a renewable natural gas fuel credit (Sec. 6426(l)), calculates it as $1 x gallons or gallon equivalents, and defines RNG and blended RNG requirements. It also creates certification and registration rules and sets a 2035 termination.
Who It Affects
RNG producers registered under 4101(a), fuel marketers, fleets and operators using RNG fuel (including trucking, boating, and aviation), and U.S. taxpayers via the credit mechanism.
Why It Matters
Promotes domestic RNG production and use, supports emissions reductions from RNG adoption, and creates a quantifiable incentive mechanism with a defined sunset to balance policy certainty with budget considerations.
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What This Bill Actually Does
The bill attaches a new RNG fuel credit to the tax code, setting a baseline credit of $1 per gallon-equivalent for RNG sold or used as fuel in recognized ways. It clarifies what counts as RNG (biomass-derived gas produced by a registered producer and certified), and it allows blended RNG to qualify if there is a prearranged contract with the producer, the contract specifies quantities and periods, and the producer provides the required certification.
The definition of gasoline gallon equivalent is set at 124,800 BTUs for non-liquid RNG.
The Five Things You Need to Know
The RNG fuel credit equals $1.00 per gallon-equivalent for RNG sold or used as fuel.
Blended RNG can qualify if preexisting contracts and producer certifications are in place.
Credit applies to RNG used in motor vehicles, motorboats, and aviation.
Credit terminates after December 31, 2035 and applies to fuel sold or used after December 31, 2025.
The bill expands registration to RNG producers and aligns related tax provisions to RNG credits.
Section-by-Section Breakdown
Every bill we cover gets an analysis of its key sections.
Short title
Establishes the act’s official name, the Renewable Natural Gas Incentive Act of 2025, for citation and reference.
RNG fuel credit—basic mechanics
Creates the RNG fuel credit under section 6426(l). The credit is the product of $1.00 and the gallons or gasoline gallon equivalents of RNG sold by the taxpayer for use as fuel in a motor vehicle, motorboat, or aviation fuel. RNG must be defined with specific production and certification requirements, and a sunset is set for December 31, 2035.
RNG definitions and blended RNG
Defines RNG as compressed or liquefied gas derived from biomass, produced by a registered producer, and subject to producer certification. Blended RNG can be treated as RNG fuel for sale if a preexisting contract exists, quantities are specified, the contract is active, and the producer provides the required certification.
Certification
Describes the certification that identifies the produced product and gallon-equivalent fuel acquired by the taxpayer, and the form/manner prescribed by the Secretary.
Application of other rules
Extends registration to RNG producers, updates anti-double-benefit rules to include RNG, requires RNG to be used domestically, and amends energy equivalency language to include RNG within the alternative fuel framework.
Payments
Authorizes payments to sellers or users of RNG fuel equal to the RNG credit amount; includes a sunset for post-2035 transactions and aligns related structural amendments across the code.
Effective date
Applies to RNG fuel sold or used after December 31, 2025, establishing an explicit transition point for the credit’s start.
Registration of RNG producers
Amends registration rules to ensure RNG producers are registered under 4101(a), tying RNG production to eligibility for the credit.
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Explore Energy in Codify Search →Who Benefits and Who Bears the Cost
Every bill creates winners and losers. Here's who stands to gain and who bears the cost.
Who Benefits
- Registered RNG producers gain a secure market incentive and a formal pathway to certify and sell RNG fuel.
- Fuel retailers and marketers with RNG assets gain an additional credit-based sales driver and clearer compliance pathways.
- Fleet operators and end users (including trucking fleets, marine operators, and aviation users) benefit from lower fuel costs and emissions reductions associated with RNG use.
- Environmental regulators and policymakers gain a clearer mechanism to promote lower-emission fuels and track adoption.
Who Bears the Cost
- The federal Treasury bears the cost of the credit through reduced tax revenue and potential outlays for credit payments.
- RNG producers incur certification, registration, and reporting costs to claim the credit.
- Retailers and marketers face administrative costs to track, certify, and report RNG transactions to justify the credit and avoid double benefits.
Key Issues
The Core Tension
The central dilemma is whether a time-limited, certification-driven RNG credit will spur durable, domestic RNG markets and emissions benefits without imposing unsustainable costs on taxpayers or imposing excessive compliance burdens on producers and retailers.
The bill creates a substantial tax incentive for RNG that must be tied to domestic production and verified through a certification process. The design relies on robust producer registration, accurate metering, and reliable certification to prevent abuse and ensure the credit translates into real emissions reductions.
A sunset at the end of 2035 introduces policy certainty but invites questions about long‑term market stability and capital planning for RNG projects. There is potential tension between the desire to accelerate RNG adoption and the fiscal cost to the Treasury, as well as the risk of administrative burden on small producers and marketers who must implement new reporting and verification requirements.
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