This chapter reviews the types of forensic evaluations and forensic expert testimony in the federal system, and the critical components of federal forensic reports, emphasizing how mental health professionals can assist the federal courts in dealing with psychiatric forensic issues. Experts' findings are usually submitted in writing but may be required to be stated at deposition or through court testimony subject to cross-examination. Reports must set forth the expert's qualifications, including publications, opinions, the facts and data relied on, and the reasons for conclusions. Although many types of federal evaluations have a time frame for completion outlined in statute, there is some flexibility in interpreting when the evaluation period actually begins. With notification to the court, most judges will approve that the evaluation process start at the time the defendant is made available to the evaluator. Although federal rules allow for them, depositions in criminal cases are not the norm.