FINAL JUDGMENT RULE
The general rule that appeals can only be taken from a final judgement. An appeal from most pretrial orders is typically considered interlocutory, and, therefore, not appealable as a final decision under 28 U.S.C. S 1291.
Collateral Order Exception To The Final-Judgment Rule:
The collateral order exception to the final-judgment rule was first announced in Cohen v. Beneficial Indus. Loan Corp., 337 U.S. 541 ('49). Cohen recognized a 'small class' of district court decisions that finally determine claims collateral to other rights asserted in the action and are too important to be deferred until the whole case is adjudicated. Id. at 546. The small class of cases defined in Cohen consists of intermediate decisions satisfying three criteria: (1) the district court's order must finally dispose of the question; (2) the issue must be completely collateral to the cause of action asserted; and (3) the decision must involve an important right that would be 'lost, probably irreparably,' if review must await final judgment. Id.
An order dissolving a preliminary injunction is an interlocutory order appealable under 28 U.S.C. S 1292(a)(1). Other, usually not appealable, orders are reviewable if their legality is inextricably bound up with the legality of the dissolution of the injunction. 28 U.S.C. S 1292(a)(1) confers jurisdiction not only over orders concerning injunctions, but also over matters inextricably bound up with the injunctive order from which appeal is taken. Transworld Airlines v. American Coupon Exch., 913 F.2d 676, 680 (9th Cir.'90). A summary judgment order that provides the legal authority to issue an injunction--that constitutes a 'necessary predicate' to complete review of the injunction--is inextricably bound up with the injunction. See id.
Where the justification for an interlocutory order is 'identical' to the justification for an interlocutory injunction, the former ruling is appealable as a merits order inextricably bound up with the injunctive ruling. Id. at 681.