The Privilege in Federal Courts
Key point 3-08.06. Federal courts generally apply state clergy-penitent privilege statutes.
In 1972 the United States Supreme Court adopted a set of rules of evidence for use in federal courts.  56 F.R.D. 184 (1972). Congress later suspended implementation of these rules pending a thorough review. In 1975, Congress enacted into law a revised version of the Federal Rules of Evidence, incorporating several changes in the rules as originally proposed by the Supreme Court. One of the most significant modifications pertained to privileged communications. The Supreme Court had proposed nine specific privileges for use in the federal courts, including the clergy-parishioner, attorney-client, husband-wife, and psychotherapist-patient privileges. Congress, however, deleted all of the Supreme Court's specific rules of privilege and replaced them with a single principle:
[T]he privilege of a witness … shall be governed by the principles of the common law as they may be interpreted by the courts of the United States in the light of reason and experience. However, in civil actions and proceedings, with respect to an element of a claim or defense as to which state law supplies the rule of decision, the privilege of a witness … shall be determined in accordance with state law.  Fed. R. Evid. 501.