As a general rule, no, the rules of evidence do not apply to ERISA disability insurance cases. The purpose of the rules of evidence is to regulate the evidence that a jury may use to reach a verdict. Since the trier of fact in an ERISA case is a federal judge and not a jury, and the trial itself is often in the form of a hearing before the federal judge, without the presentation of witnesses or evidence outside of the administrative record, the rules of evidence have no application.
Unfortunately, what this also means is that often there is no right or access to discovery in ERISA litigation; with the exception of some limited discovery into the insurance company’s conflict of interest. However, conflict of interest discovery is only conducted in order to level the playing field with the disability insurance company and eliminate the deference afforded to them through the policy’s discretionary clause. There is no right to depose or call witnesses at trial or to even subpoena documents, with the exception of the administrative record, which is designated by the Plan Administrator and the disability insurance company.