In the Supreme Court’s 2024–2025 term, 42% of decided cases ended in a 9-0 ruling, and the term before that hit 44%. Over the past decade, unanimous decisions on the Roberts Court have consistently landed between roughly 40% and 65% of argued cases, making a 9-0 Supreme Court decision the single most common voting outcome in most years. The sharp 5-4 and 6-3 splits that dominate news coverage are the exception, not the rule.
The Rate Across Recent Terms
The Roberts Court’s unanimity numbers have moved within a fairly narrow band, though the recent direction is downward. The 2013–2014 term reached about 64%, a modern peak. From 2010 through 2016, unanimous rulings regularly accounted for half of the Court’s output or more. The 2022–2023 term came in around 50%, followed by 44% in 2023–2024 and 42% in 2024–2025.
Even at the low end of that range, no other voting configuration comes close. A 42% unanimity rate still means more cases end 9-0 than end 6-3, 5-4, or any other split. Whether the recent decline reflects a shifting docket, greater ideological division, or ordinary term-to-term fluctuation is too early to say.
What Counts as a 9-0 Decision
The percentage you see reported depends on how “unanimous” is defined. Legal commentators generally use three measures, and the count changes with each one.
- Unanimous in judgment. All nine justices agree on who wins and who loses, but some may write separate concurrences with different reasoning. By this broadest measure, the Court reaches a unanimous result in roughly two-thirds of its cases in some terms.
- Unanimous in opinion. Every justice joins at least part of the majority opinion, agreeing on both the outcome and at least some of the reasoning.
- Fully unanimous. Every justice signs the entire majority opinion without writing or joining any separate concurrence.
Headline statistics usually rely on the first or second measure. The narrower “fully unanimous” count runs meaningfully lower. In the 2013–2014 term, 66% of cases were unanimous in judgment, but only 38% were fully unanimous with no separate writings. That gap shows how often justices agree on the winner while still wanting to explain the reasoning their own way.
Why So Many Cases End 9-0
Subject matter is the strongest predictor. Cases involving statutory interpretation, where the justices are reading the text of a law Congress wrote and deciding what it means, produce far more unanimity than cases asking the Court to interpret the Constitution. When the words of a statute are reasonably clear, judicial philosophy matters less than reading comprehension.
Bankruptcy law, pension and retirement plan disputes, tax code questions, and procedural rules like filing deadlines are the bread and butter of the unanimous docket. A recent example is Cunningham v. Cornell University, a retirement plan case where every justice joined a single opinion.1Supreme Court of the United States. Cunningham v. Cornell University These disputes turn on specific statutory language rather than broad principles like due process or equal protection, which leaves less room for ideological disagreement.
Precedent also drives agreement. When a new case falls squarely within a rule the Court settled years ago, most justices will apply the existing framework even if they might have decided the original case differently. Overturning precedent requires a special justification, so many cases get resolved through straightforward application of settled law.
Constitutional cases are where the splits happen. Questions about the scope of the First Amendment, the reach of executive power, or the meaning of equal protection invite fundamentally different judicial philosophies to collide. Academic research has found that civil liberties cases produce unanimity at significantly lower rates than cases involving judicial procedure or statutory questions.
Famous 9-0 Rulings
Some of the most consequential rulings in American history were unanimous, which complicates the assumption that 9-0 cases are always low-profile technical disputes. Brown v. Board of Education (1954), the decision that declared racial segregation in public schools unconstitutional, was 9-0. Chief Justice Earl Warren worked deliberately to secure a unanimous opinion because he understood that a divided Court would have given segregationists room to resist.
Cooper v. Aaron (1958) followed up on Brown when Arkansas officials refused to desegregate. The Court unanimously held that states cannot nullify federal court decisions, and all nine justices individually signed the opinion to emphasize its authority. New York Times v. Sullivan (1964), which established the “actual malice” standard for public officials suing for libel, was also unanimous.2United States Courts. Supreme Court Landmarks
More recently, the Court ruled unanimously in United States v. Jones (2012) that attaching a GPS tracker to a suspect’s car without a warrant constituted a search under the Fourth Amendment, and in Riley v. California (2014) that police need a warrant to search a cell phone during an arrest. When a legal principle is clear enough or a government overreach obvious enough, the entire Court will say so together.
Why the Number Surprises People
The disconnect between perception and reality comes down to coverage. A 9-0 ruling clarifying the tax treatment of a particular type of trust generates no public interest. A 5-4 decision on affirmative action generates weeks of commentary, public protests, and political fundraising. Journalists focus on the cases where something is at stake politically, so the contentious minority of the docket gets disproportionate attention.
That doesn’t mean the close splits don’t matter. The 5-4 cases tend to involve the rights and policies that affect daily life most directly. But anyone trying to understand how often the Court actually agrees should know that quiet consensus, not dramatic division, is the institution’s default mode. In a typical recent term, roughly four in ten decided cases produce a 9-0 outcome, and by the broadest measure of agreement the figure climbs closer to two in three.