42 CFR 430.88 - Evidence.
(a) Evidentiary purpose. The hearing is directed to receiving factual evidence and expert opinion testimony related to the issues involved in the proceeding. Argument is not received in evidence. It must be presented in statements, memoranda, or briefs, as determined by the presiding officer. Brief opening statements, concerning the party's position and what he or she intends to prove, may be made at hearings.
(b) Testimony. Testimony is given orally under oath or affirmation by witnesses at the hearing. Witnesses are available at the hearing for cross-examination by all parties.
(c) Stipulations and exhibits. Two or more parties may agree to stipulations of fact. Those stipulations, and any exhibit proposed by any party, are exchanged before the hearing if the presiding officer so requires.
(d) Rules of evidence. (1) Technical rules of evidence do not apply to hearings conducted under this subpart. However, rules or principles designed to ensure production of the most credible evidence available and to subject testimony to test by cross-examination are applied by the presiding officer when reasonably necessary.
(2) A witness may be cross-examined on any matter material to the proceeding without regard to the scope of his or her direct examination.
(3) The presiding officer may exclude irrelevant, immaterial, or unduly repetitious evidence.
(4) All documents and other evidence offered or taken for the record are open to examination by the parties and an opportunity is given to refute facts and arguments advanced on either side of the issues.