The date of the enactment of the Revenue Reconciliation Act of 1990, referred to in subsec. (b)(5), is the date of enactment of Pub. L. 101–508, which was approved Nov. 5, 1990.

Section 9901(6) of the William M. (Mac) Thornberry National Defense Authorization Act for Fiscal Year 2021, referred to in subsec. (c)(1), means section 9901(6) of Pub. L. 116–283, but probably should be a reference to section 9901(8) of the Act, which defines “foreign entity of concern” and which is classified to section 4651(8) of Title 15, Commerce and Trade.

The date of the enactment of this section, referred to in subsec. (d)(2)(B), is the date of enactment of Pub. L. 117–167, which was approved Aug. 9. 2022.

A prior section 48D, added Pub. L. 111–148, title IX, § 9023(a), Mar. 23, 2010, 124 Stat. 877, provided for a qualifying therapeutic discovery project credit, prior to repeal by Pub. L. 115–141, div. U, title IV, § 401(d)(3)(A), Mar. 23, 2018, 132 Stat. 1209.

2025—Subsec. (a). Pub. L. 119–21 substituted “35 percent” for “25 percent”.

Pub. L. 119–21, title VII, § 70308(b), July 4, 2025, 139 Stat. 201, provided that: “The amendments made by this section [amending this section] shall apply to property placed in service after December 31, 2025.”

Section applicable to property placed in service after Dec. 31, 2022, and, for any property the construction of which begins prior to Jan. 1, 2023, only to the extent of the basis thereof attributable to the construction, reconstruction, or erection after Aug. 9, 2022, see section 107(f) of Pub. L. 117–167, set out as an Effective Date of 2022 Amendment note under section 905 of Title 2, The Congress.