A claim is "ripe" when the facts of the case have matured into an existing substantial controversy warranting judicial intervention. Article III, Section 2, Clause 1, of the U.S. Constitution requires federal courts to decide only actual cases and controversies. The requirement that a claim be ripe for judicial review is an issue of subject matter jurisdiction closely related to the "standing" requirement.
The question of ripeness often arises in cases where the harm asserted by the plaintiff has not yet occurred. Because courts are not permitted to decide merely hypothetical questions or possibilities, the court must determine whether the issues are fit for judicial review. A case is typically considered ripe if it presents a purely legal issue, or if further development of the facts will not render the issue more concrete.
For Supreme Court decisions focusing on the "ripeness" issue, see, e.g.; Reno v. Catholic Social Servs., 509 U.S. 43 (1993); Lucas v. South Carolina Coastal Council, 505 U.S. 1003 (1992) and Abbott Laboratories v. Gardner, 387 U.S. 136 (1967)