The RNG Coalition has welcomed the US Treasury Department's release of proposed regulations for the Section 45Z Clean Fuel Production Tax Credit, as authorised by the 2022 Inflation Reduction Act and amended by last year's One Big Beautiful Bill Act.
"Today's 45Z proposed rule is a positive step towards providing the clarity and certainty that renewable natural gas producers require," said RNG Coalition Senior Director of Federal Government Affairs Geoffrey Dietz. "We thank the Treasury Department and Trump administration for listening to the input provided by industry.
"In particular, the proposal appears to address lack of clarity on what constitutes a 'qualified sale', fortifies industry's understanding of the 'suitable for use' provision, and anticipates offering flexibility related to fuel specifications.
"Key questions however remain unanswered, and some concerns need to be addressed. The RNG industry is awaiting an updated version of the 45ZCF-GREET model, which should introduce new RNG production pathways, such as food waste-derived fuel, and help provide clearer direction on the emissions rates for feedstocks, including animal manures. We are also eager to address certain limitations around the use of RNG as a process input, or feedstock for the production of other qualifying transportation fuels."
Passage of the One Big Beautiful Bill Act in July made several changes to improve the tax credit, such as extending its duration and requiring that fuels derived from animal manure, namely dairy and swine, receive specific lifecycle emissions rates. The RNG Coalition filed detailed comments with Treasury in October 2025, stating that the Treasury Department must ensure a flexible, practical programme that serves to help unleash US RNG and renewable gas-derived fuels, whilst also supporting local and rural economies.
Industry also urged that RNG producers require as much certainty as possible with respect to applicable rules and guidance for credit eligibility. Substantial capital investments are required to upgrade biogas to RNG, and return on investment requires long-term stability and regulatory certainty.
Dietz said the RNG Coalition looks forward to providing comments on the proposal to the Treasury Department and intends to testify at the hearing in May.
