By James J. Mangraviti, Jr., Esq.

Introduction – What is an Expert Witness?

Before we delve into what is included in an expert witness report, we should briefly discuss what an expert witness is.  Expert witnesses (also known as opinion witnesses) are witnesses in court cases who are allowed to offer their professional opinions on relevant matters.  This is different than a fact witness who is typically restricted to what they have seen, heard, smelled, felt, or tasted. Expert witnesses are qualified to give opinions based upon their knowledge, skills, training, education, or experience. See Federal Rule of Evidence 702.

Why is an Expert Witness Report Drafted?

An expert witness report may be drafted for a variety of reasons.

  1. An expert witness report may be required in the jurisdiction in question. For example, for civil cases litigated in federal court expert witnesses who have been specially retained (as opposed to say a treating physician), must prepare and sign a report in conformity with Federal Rule of Civil Procedure 26.
  2. An expert witness report may be drafted to help educate retaining counsel as to the expert’s findings and conclusions.
  3. An expert witness report may be drafted to share with opposing counsel in an effort to settle the case.
  4. In cases heard through arbitration or certain administrative proceedings (where hearsay rules do not apply), the expert witness report might serve as the expert’s direct testimony at the hearing.
  5. Finally, an expert witness report may be drafted to help the expert in question to flesh out their own opinions. Additionally, a well-drafted expert witness report is a roadmap to the expert’s likely testimony which will help the expert witness to prepare for both deposition and trial.

What is Included in an Expert Witness Report?

What is included in an expert witness report will depend upon many factors including the jurisdiction the case is pending in, the type of opinion(s) the expert witness is offering, and the preferences of the expert witness in question.

In certain jurisdictions there are minimum requirements for what is included in an expert witness report.  For example, per Federal Rule of Civil Procedure 26 (a)(2)(B), an expert witness report must contain at least:

“(i) a complete statement of all opinions the witness will express and the basis and reasons for them;

(ii) the facts or data considered by the witness in forming them;

(iii) any exhibits that will be used to summarize or support them;

(iv) the witness’s qualifications, including a list of all publications authored in the previous 10 years;

(v) a list of all other cases in which, during the previous 4 years, the witness testified as an expert at trial or by deposition; and

(vi) a statement of the compensation to be paid for the study and testimony in the case.”

Where minimum requirements for what is included in an expert witness report are not specified by law, the following can serve as a good road map:

  1. A short statement including who retained you, when your were retained, and what exactly retaining counsel asked you to opine on.
  2. A description of your relevant qualifications including drilling down and including details of the qualifications you have regarding the specific issues you have been asked to opine on.  Experts also typically attach their current CV to the end of their report.
  3. Materials Reviewed. A detailed list of the records, depositions, photographs and other material you have reviewed.
  4. Site Visit/Examination. If applicable – a summary of your hands on investigation in the case at hand.
  5. A narrative of what you are assuming to be the relevant facts in this case.
  6. A numbered list of your opinions. Each opinion should be stated clearly and confidently.  The detailed reasoning for each opinion should follow each opinion. Cites to references should be included as appropriate.
  7. Boilerplate language. This often states that your opinions are to a reasonable degree of certainty, they were based on the information available to you as of the date of the report, and that you reserve the right to modify your opinions if you are presented with additional information.
  8. Signature of the expert witness. The expert witness report should be signed by the expert. Note that expert witness reports are typically not signed under the pains and penalties of perjury.
  9. Date of Report. The date your report was issues should be included someplace. This could be at the beginning of the report, the end of the report, or on each page footer.
  10. Line numbers in the left margin. These can easily be added in Microsoft Word.
  11. Page numbers.


I hope that the above has served as a concise and helpful summary of what is included in an expert witness report.

About the Author

James J. Mangraviti, Jr., Esq., is a Principal of SEAK, IncThe Expert Witness Training Company. He has trained many thousands of expert witnesses on report writing, testifying skills and practice management/business development. Jim can be reached at 978-276-1234 or .