Format: 

Plaintiff v. Defendant, Volume Reporter Page (Court Year).

Examples: 

Town of Greece v. Galloway, 134 S. Ct. 1811 (2014).

In-text: (Town of Greece v. Galloway, 2014)

N.Y. State Rifle & Pistol Ass'n v. Cuomo, 990 F. Supp. 2d 349 (W.D.N.Y. 2013).

In-text: (N.Y. State Rifle & Pistol Ass'n v. Cuomo, 2013)

Notes: 

Do not include the court name for Supreme Court cases. Use appropriate abbreviations whenever possible including for the case name (e.g. Ass'n), reporter (e.g. S. Ct.), and deciding court (W.D.N.Y.). Case names are italicized in-text, but are not italicized in the References list.

Source:
APA - A7.03