Rev. Proc. 2020-50, page 1122.

This revenue procedure provides guidance for taxpayers wishing to apply §§ 1.168(k)-2 and 1.1502-68 of the Income Tax Regulations, or to rely on the proposed regulations under § 168(k) (REG-106808-19) published in 2019 for: (1) certain depreciable property acquired and placed in service by the taxpayer after September 27, 2017; (2) certain plants planted or grafted by the taxpayer, as applicable, after September 27, 2017; and (3) components acquired or self-constructed by the taxpayer after September 27, 2017, of certain larger self-constructed property. If the taxpayer retroactively applies §§ 1.168(k)-2 and 1.1502-68, or relies on the 2019 proposed regulations, this revenue procedure also allows the taxpayer to make a late election under § 168(k)(5), (k)(7), or (k)(10), § 1.168(k)-2(c) of the 2020 final regulations or the 2019 proposed regulations, or § 1.1502-68(c)(4), or to revoke an election under § 168(k)(5), (k)(7), or (k)(10), or § 1.168(k)-2(c) of the 2019 proposed regulations.

T.D. 9919, page 1073. Nonresident aliens and foreign corporations are taxable in the United States on taxable income that is effectively connected with the conduct of a trade or business in the United States. These final regulations provide rules for determining the amount of effectively connected gain or loss recognized by a nonresident alien individual or foreign corporation from the sale or exchange of an interest in a partnership that is engaged in a trade or business within the United States. TD 9919. Published November 6, 2020.