SECTION 1. PURPOSE

This notice provides guidance to taxpayers applying the substantial improvement provision of § 1400Z-2(d)(2)(D)(ii) of the Internal Revenue Code (Code), ¹ as amended by § 70421(c)(4)(C) of Public Law 119-21, 139 Stat. 72, 227 (July 4, 2025), commonly known as the One, Big, Beautiful Bill Act (OBBBA), for certain improvements to property located in a qualified opportunity zone (QOZ) listed

in Notice 2018-48, 2018-28 I.R.B. 9, or Notice 2019-42, 2019-29 I.R.B. 352, that is comprised entirely of a “rural area.” This notice does not provide any guidance regarding the forthcoming round of opportunity zone nominations, certifications, and designations authorized by the OBBBA, which the Department of the Treasury (Treasury Department) and the Internal Revenue Service (IRS) will address in the future.