Federal Statutes (USC, Pub L., Stat):
In-Text Citation: Child Abuse Prevention and Treatment Act of 1974
If a formal name of the law is not available (e.g., there is only a U.S. Code citation), some authors include the legal citation in the text only, e.g.:18 U.S.C. § 2258, and exclude it from the References list.
APA prefers the law be identified by name and entered into the References list whenever possible.
You can get the § symbol by typing ALT 0167
References List Format 1 (Name of law with US Code citation only):
Name of law, title # U.S.C. § section #.
Child Abuse Prevention and Treatment Act of 1974, 42 USC §§5101–5106.
References List Format 2 (with Public Law and/or Statutes at Large information):
Name of law, Pub. L. ##-##, volume Stat. page, codified as amended at title U.S.C. § section #.
Child Abuse Prevention and Treatment Act of 1974, Pub. L. 93-247, 88 Stat. 4, codified as amended at 42 U.S.C. §§5101–5106.
More information is available on the APA Blog