APA rule A7.04: In text, give the popular or official name of the act (if any) and the year of the act. In the reference list entry, include the source and section number of the statute, and in parentheses, give the publication date. For example, the Tennessee Health Care Decision Act:
In text: (Tennessee Health Care Decision Act, 2004)
or Tennessee Health Care Decision Act (2004)
or Tennessee Health Care Decision Act of 2004
Reference list:
Tennessee Health Care Decision Act, Tenn. Code Ann. §68-11-1803 (2004).
APA style blog has more examples of citing federal statutes.