Supreme Court justices, court of appeals judges, and district court judges are nominated by the President and confirmed by the United States Senate, as stated in the Constitution.
The names of potential nominees are often recommended by senators or sometimes by members of the House who are of the President's political party. The Senate Judiciary Committee typically conducts confirmation hearings for each nominee. Article III of the Constitution states that these judicial officers are appointed for a life term.
The Constitution sets forth no specific requirements for judges. However, members of Congress, who typically recommend potential nominees, and the Department of Justice, which reviews nominees' qualifications, have developed their own informal criteria.