The Treasury Department and the Internal Revenue Service recently released IRS Notice 2025-10 and 2025-11, offering guidance on the Clean Fuel Production Credit under section 45Z of the Internal Revenue Code. This credit, available for clean fuels produced and sold between January 1, 2025, and December 31, 2027, is a successor to previous fuel production and blending credits, now being tech-neutral. The credit amount varies depending on the fuel type and emissions rate, encompassing fuels like sustainable aviation fuel and highway vehicle fuel. The Notice outlines how taxpayers can calculate the Clean Fuel Production Credit, with specific details on the 'emissions factor' for the fuel produced and sold. The use of the 45ZCF-GREET model to determine the Emissions Rate is mandatory for most taxpayers, although fuels not covered in the model await further guidance from the Treasury. Additionally, the Notice provides clarity on terms like 'suitable for use' in vehicles, qualifying sales criteria, and the production process. It highlights that a fuel's practical fitness for use in vehicles is crucial and emphasizes that actual use in vehicles is not mandatory for eligibility. Furthermore, the definition of 'production' requires substantial processing and chemical transformation, excluding minimal activities like biodiesel stabilization. Overall, the new guidance aims to streamline the process for taxpayers seeking the Clean Fuel Production Credit, promoting clean fuel production in the United States and setting clear criteria for eligibility and compliance.