Collateral Order Doctrine Law and Legal Definition

Collateral order doctrine is an exception in federal courts to the general rule that only final judgments are appealable.This judicially created doctrine allows appeal from an interlocutory order that conclusively determines an issue wholly separate from the merits of the action and that is effectively unreviewable on appeal from a final judgment. This is also termed as Cohen doctrine as this doctrine evolved in the case of Cohen v. Beneficial Loan Corp., 337 U.S. 541, 546 (1949). The doctrine was restricted in Digital Equipment Corp. v. Desktop Direct Inc., 511 U.S. 863 (1994), which added an explicit importance criterion to the test for interlocutory appeals, holding that relief on a claim of immunity from suit because of a previous settlement agreement could not come through interlocutory appeal.