Notice 2024-49, 2024-26 I.R.B. 1781

(released May 31, 2024), provides guidance on the section 45Z registration requirements, including the time, form, and manner of registration. Section 3 of Notice 2024-49 also provides general definitions, initial definitions of SAF and non-SAF transportation fuels, and an initial, non-exclusive list of primary feedstocks, to help taxpayers applying for registration identify fuels and primary feedstocks that may qualify for the section 45Z credit. Notice 2025-10, 2025-6 I.R.B. 682 (released January 10, 2025), discussed later in this Background section, modifies and supersedes these definitions, and replaces them with the definitions in the Appendix to Notice 2025-10.

E. Treasury Decision 9998 (PWA Regulations)

The Treasury Department and the IRS published Treasury Decision 9998 in the Federal Register (89 FR 53184, June 25, 2024), which finalized regulations concerning the PWA requirements under several sections of the Code (PWA Regulations), including section 45Z. Section 1.45Z-3 provides rules on the application of the PWA requirements to section 45Z. The preamble to the PWA Regulations contains a detailed discussion of the PWA requirements, including applicability dates and transition rules with respect to the section 45Z credit. These proposed regulations only address § 1.45Z-3 for context and to the extent necessary to

clarify the rules herein. The PWA Regulations are otherwise outside the scope of this rulemaking.

F. Fact Sheet FAQs

A section 45Z Fact Sheet, FS-2024-25 (released July 10, 2024), provides answers to certain frequently asked questions (FAQs) on the section 45Z registration requirements. This Fact Sheet is available at https://www.irs.gov/newsroom/ frequently-asked-questions-about-apply- ing-for-registration-for-the-clean-fuel- production-credit-under-ss-45z .

G. Notice 2025-10 (Notice of Intent to Propose Rules)