First, higher courts bind lower courts within their particular state or circuit. With the
exception of the U.S. Supreme Court, courts of appeals and state courts do not bind courts
outside the state or circuit in which they are located. That is, a federal Supreme Court decision is
binding on all lower federal courts, both circuit courts of appeals and district courts. A federal
circuit decision is binding on all federal district courts within its circuit, but not federal courts in
other circuits. For example, a decision of the U.S. Court of Appeals for the Ninth Circuit binds
the U.S. district courts within the Ninth Circuit, but not federal courts in any other circuit.
However, a district court or trial court decision would not bind higher courts. A decision by a
state’s highest court is binding on all appeals courts and trial courts in that state, but not on state
courts in other states, and usually, a state court of appeals’ decision binds state trial courts in that
state.
Second, with the exception of the U.S. Supreme Court, federal courts bind only other
federal courts, not state courts. Thus, a decision by the U.S. Court of Appeals for the Ninth
Circuit, a federal court, is binding on federal district courts within the boundaries of the Ninth
Circuit. It is not binding on California state courts, even though California is geographically
within the Ninth Circuit. Similarly, state courts bind only other state courts within the state.
A decision of the California Supreme Court would thus bind other California state courts, not
state courts in any other state. However, sometimes a federal court must apply a state’s law. In
that case, the state’s interpretation of that law is binding on the federal court. Therefore, a
California Supreme Court decision on a matter of California law would bind federal courts on
that state law issue. Similarly, state courts must sometimes decide issues of federal law, but they
are not bound by federal courts except the U.S. Supreme Court. A decision of the U.S. Supreme
Court, a federal court, is binding on state courts when it decides an issue of federal law, such as
Constitutional interpretation.
FROM:
https://www.law.georgetown.edu/wp-content/uploads/2018/07/Which-Court-is-Binding-HandoutFinal.pdf
