In Massachusetts v. EPA, the Supreme Court for the first time clearly gave greater standing rights to states than ordinary citizens. The Court, however, failed to explain to what extent or when states are entitled to more lenient standing. This Article concludes that the Court has historically given states preferential status in federal courts when a state files a parens patriae suit based on the state's quasi-sovereign interest in the health and welfare of its citizens or the natural resources of its inhabitants and territory. A quasi-sovereign interest is inherently less concrete and particularized than the types of injuries that individual citizens need for standing, yet the Court has allowed states standing to protect their general interest in their citizens' health and welfare. This Article proposes that courts relax the immediacy and redressability prongs of the standing test when states bring parens patriae suits to protect their quasi-sovereign interest in the health, welfare, and natural resources of their citizens. This proposed standing test would be similar to the relaxed standing test for procedural rights plaintiffs but is based on the Court's historic parens patriae decisions. By using and refining the Court's procedural rights standing test as a model, this Article proposes a workable standing test for states.