20 CFR § 404.950 - Presenting evidence at a hearing before an administrative law judge.
(a) The right to appear and present evidence. Any party to a hearing has a right to appear before the administrative law judge, either by video teleconferencing, in person, or, when the conditions in § 404.936(c)(2) exist, by telephone, to present evidence and to state his or her position. A party may also make his or her appearance by means of a designated representative, who may make the appearance by video teleconferencing, in person, or, when the conditions in § 404.936(c)(2) exist, by telephone.
(b) Waiver of the right to appear. You may send the administrative law judge a waiver or a written statement indicating that you do not wish to appear at the hearing. You may withdraw this waiver any time before a notice of the hearing decision is mailed to you. Even if all of the parties waive their right to appear at a hearing, we may notify them of a time and a place for an oral hearing, if the administrative law judge believes that a personal appearance and testimony by you or any other party is necessary to decide the case.
(c) Admissible evidence. Subject to the provisions of § 404.935, the administrative law judge may receive any evidence at the hearing that he or she believes is material to the issues, even though the evidence would not be admissible in court under the rules of evidence used by the court.
(1) When it is reasonably necessary for the full presentation of a case, an administrative law judge or a member of the Appeals Council may, on his or her own initiative or at the request of a party, issue subpoenas for the appearance and testimony of witnesses and for the production of books, records, correspondence, papers, or other documents that are material to an issue at the hearing.
(2) Parties to a hearing who wish to subpoena documents or witnesses must file a written request for the issuance of a subpoena with the administrative law judge or at one of our offices at least 10 business days before the hearing date, unless you show that your circumstances meet the conditions described in § 404.935(b). The written request must give the names of the witnesses or documents to be produced; describe the address or location of the witnesses or documents with sufficient detail to find them; state the important facts that the witness or document is expected to prove; and indicate why these facts could not be proven without issuing a subpoena.
(3) We will pay the cost of issuing the subpoena.
(4) We will pay subpoenaed witnesses the same fees and mileage they would receive if they had been subpoenaed by a Federal district court.
(e) Witnesses at a hearing. Witnesses you call may appear at a hearing with you in the same manner in which you are scheduled to appear. If they are unable to appear with you in the same manner as you, they may appear as prescribed in § 404.936(c)(4). Witnesses called by the administrative law judge will appear in the manner prescribed in § 404.936(c)(4). They will testify under oath or affirmation unless the administrative law judge finds an important reason to excuse them from taking an oath or affirmation. The administrative law judge may ask the witness any questions material to the issues and will allow the parties or their designated representatives to do so.
(f) Collateral estoppel - issues previously decided. An issue at your hearing may be a fact that has already been decided in one of our previous determinations or decisions in a claim involving the same parties, but arising under a different title of the Act or under the Federal Coal Mine Health and Safety Act. If this happens, the administrative law judge will not consider the issue again, but will accept the factual finding made in the previous determination or decision unless there are reasons to believe that it was wrong.