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The U.S. Supreme Court Explained

Updated: October 30, 2026

The Supreme Court is the highest court in the United States and the head of the judicial branch. It has nine seats, its justices are appointed by the president and confirmed by the Senate, and they serve for life so they can decide cases independently of politics. Its most important power is deciding whether a law goes against the Constitution.

Where the Supreme Court comes from

Article III of the Constitution says the judicial power of the United States belongs to "one supreme Court" and to lower courts that Congress creates. The Constitution does not fix the number of justices. Congress sets it by law. The first Supreme Court in 1789 had six justices, and the number has been nine since 1869.

Lower federal courts include district courts (trial courts) and courts of appeals (circuit courts). The 2025 civics test accepts both "Supreme Court" and "federal courts" for "What is one part of the judicial branch?"

How justices are chosen

  1. A seat opens when a justice retires, dies, or (in theory) is removed through impeachment.
  2. The president nominates a replacement.
  3. The Senate Judiciary Committee holds hearings.
  4. The full Senate votes to confirm or reject.

This is a classic check and balance: the executive branch picks, the legislative branch approves, and the judicial branch then works independently. See the three branches of government for how the branches limit each other.

The Chief Justice of the United States leads the court. As of the USCIS test updates page in 2026, that is John Roberts. Because it can change, always verify on uscis.gov/citizenship/testupdates before your interview.

Why lifetime appointments?

Justices (and most other federal judges) serve "during good behaviour," which in practice means for life or until they choose to retire. The idea is that judges who do not need to win re-election or please a political party can follow the law even when it is unpopular.

The 2025 civics test asks exactly this. For "Supreme Court justices serve for life. Why?" the accepted answers are to be independent (of politics) and to limit outside (political) influence.

Judicial review - the court's biggest power

The Supreme Court can decide that a federal or state law, or an action by the government, goes against the Constitution and is therefore invalid. This power is called judicial review. It is not spelled out word for word in the Constitution. The court established it in the 1803 case Marbury v. Madison, and it has been a basic part of American government ever since.

For the test, the answers to "What does the judicial branch do?" are: reviews laws, explains laws, resolves disputes (disagreements) about the law, and decides if a law goes against the Constitution.

How a case reaches the Supreme Court

The Supreme Court does not choose issues on its own or give advice. A real legal dispute has to work its way up:

  1. A case starts in a trial court (federal or state).
  2. The losing side appeals to a higher court.
  3. The losing side at that level can ask the Supreme Court to hear the case, usually through a petition for a writ of certiorari.
  4. The court accepts only a small fraction of the thousands of petitions it receives each year, typically cases with major constitutional questions or where lower courts disagree.
  5. Lawyers file written briefs, then argue in front of the justices.
  6. The justices vote. A majority, usually five of the nine, decides the case, and one justice writes the opinion of the court. Others may write concurring or dissenting opinions.

The court's term traditionally begins on the first Monday in October, and many major decisions are announced near the end of the term in June.

Landmark cases worth knowing

You will not be asked about specific cases on the civics test, but a few help you understand the court's role, especially for history questions:

Supreme Court questions on the 2025 civics test

From the USCIS list of 128 questions:

That is nine questions on one topic, so it is worth learning well. Practice them alongside the rest of the civics questions.

Common mix-ups

Frequently asked questions

How many justices are on the Supreme Court?

Nine. The number is set by Congress and has been nine since 1869.

Who is the Chief Justice of the United States?

As of the USCIS test updates page in 2026, John Roberts. Check uscis.gov/citizenship/testupdates before your interview in case it changes.

How long do Supreme Court justices serve?

For life, or until they retire. USCIS accepts "(for) life," "lifetime appointment," and "(until) retirement."

Who chooses Supreme Court justices?

The president nominates them and the Senate must confirm them. On the civics test, the answer to "Who appoints federal judges?" is the President.

How many justices are needed to decide a case?

Usually five, a majority of the nine.

Prepare for the civics test with Civio: every official question from the 2025 USCIS civics test, Exam Mode with your state's questions, and spaced repetition.

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Informational article, not legal advice. Civio is not affiliated with USCIS or any government agency; always check current requirements at uscis.gov.

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