485 U.S. 80 (1988)
Peralta v. Heights Medical Center is a cornerstone Supreme Court decision on due process, service of process, and default judgments.
Does the Due Process Clause permit a state to condition relief from a default judgment entered without proper service of process on the defendant's showing of a meritorious defense to the underlying action?
Due process requires notice reasonably calculated, under all the circumstances, to apprise interested parties of the pendency of the action and afford them an opportunity to present their objections. A judgment entered without constitutionally adequate notice and personal jurisdiction is void and must be set aside; a state may not condition vacatur of such a judgment on the defendant's demonstration of a meritorious defense. See Mullane v. Central Hanover Bank & Trust Co., 339 U.S. 306 (1950); Armstrong v. Manzo, 380 U.S. 545 (1965).
No. A state may not require a defendant to show a meritorious defense as a condition to setting aside a default judgment that was entered without proper service and notice. The default judgment violates due process and must be vacated.
Peralta is a leading case on void judgments and due process. It clarifies that when service of process is constitutionally deficient, the resulting default judgment is void and must be vacated without any requirement that the defendant show a meritorious defense or lack of prejudice. The case is frequently invoked in motions to vacate under Rule 60(b)(4) and state equivalents, and it informs exam analysis on personal jurisdiction, service of process, and the constitutional limits on state procedural rules. For practice, it cautions plaintiffs to ensure proper service and reminds courts that procedural shortcuts cannot be justified by assumptions about the merits.