Mootness

Mootness is the justiciability counterpart to ripeness — while ripeness asks whether a case is too early, mootness asks whether it is too late. Under Article III, federal courts may only adjudicate live cases and controversies. If events subsequent to filing render the dispute no longer live, the case is moot and must be dismissed.

A case becomes moot when the plaintiff's injury has been fully remedied, the challenged conduct has ceased, or circumstances have changed such that a judicial decision would have no practical effect. The classic example is a student challenging a school policy who graduates before the case is resolved — the student no longer has a personal stake in the outcome.

Several important exceptions prevent strategic mootness and ensure that recurring issues receive judicial attention. The "capable of repetition yet evading review" exception applies when the challenged action is too short in duration to be fully litigated before it expires and there is a reasonable expectation that the same party will be subjected to the same action again. Roe v. Wade famously applied this exception, as pregnancy would always end before the case could be fully litigated.

The voluntary cessation exception provides that a defendant cannot moot a case simply by voluntarily stopping the challenged conduct if there is a reasonable possibility that the behavior could recur. The defendant bears the heavy burden of showing that the conduct cannot reasonably be expected to start again. In class actions, the named plaintiff's claim may become moot, but the case continues as long as the class retains a live controversy.

On exams, mootness arises when facts change during litigation. Students should check whether exceptions apply before concluding a case is moot.