Q. How do I cite a public law in APA?

Citing Federal Statutes

Cite a statute in its location in the U.S. Code. Alternatively, cite the statute in its original publication in the Statutes at Large, rather than in the code. This is usually done when the statute is an appropriation, has been repealed, or has its contents scattered in different parts of the Code.

Basic form
Name of Act § Section number, Volume number U.S.C. § Section number (Year).
Name of Act, Pub. L. No. Number , § Section number, Volume number Stat. Page number.

Examples
National Environmental Policy Act of 1969 § 102, 42 U.S.C. § 4332 (1994).
Americans with Disabilities Act of 1990, Pub. L. No. 101-336, § 2, 104 Stat. 328 (1991).

An in-text citation for public laws, legal codes, statutes, regulations, and cases is (Name year), for example (New York Times Co. v. Tasini, 2001)