Non-Retained Expert Witness Disclosure: Is an Expert Report Required for a Treating Physician’s Testimony?

Emily Lou Steenwyk

March 19, 2025

 

In legal proceedings, treating physicians often play a crucial role as witnesses. However, a key question arises: Do treating physicians need to submit an expert report to testify? The answer depends on whether they are classified as retained or non-retained expert witnesses under the Federal Rules of Civil Procedure (FRCP).

This article breaks down the legal requirements, disclosure obligations, and best practices for using treating physicians as witnesses. Understanding these rules ensures that attorneys comply with disclosure requirements and avoid potential legal pitfalls.


Understanding Non-Retained Expert Witnesses

A non-retained expert witness is an individual with specialized knowledge relevant to a case but who is not specifically hired to provide expert testimony. Treating physicians typically fall into this category because their testimony is based on their direct treatment of a patient rather than an independent review of case materials.

Non-Retained vs. Retained Experts: Key Differences

  • Non-retained experts, like treating physicians, form opinions as part of their normal professional duties.
  • Retained experts are specifically hired to analyze evidence and provide expert opinions in litigation.

The distinction is important because retained experts must submit a full written report, while non-retained experts have limited disclosure requirements.


Federal Rules of Civil Procedure: Expert Witness Disclosure

Under Rule 26 of the Federal Rules of Civil Procedure (FRCP), different disclosure requirements apply to retained and non-retained experts.

Rule 26(a)(2)(A) – Disclosure of Expert Witnesses
Any party intending to use an expert witness must disclose that expert in pretrial proceedings.

Rule 26(a)(2)(B) – Retained Experts’ Report Requirements
A retained expert witness must provide a detailed written report, including:

  • A full statement of all opinions and the basis for them.
  • A list of data and facts considered in forming opinions.
  • Any exhibits supporting the opinions.
  • The expert’s qualifications, including a list of publications from the past 10 years.
  • A list of cases in which the expert has testified in the past 4 years.
  • A statement of compensation for study and testimony.

Rule 26(a)(2)(C) – Non-Retained Expert Disclosure
For non-retained experts like treating physicians, a full report is NOT required, but the disclosing party must provide:

  • The subject matter of the expert’s testimony.
  • A summary of the facts and opinions the expert will present.

This limited disclosure reflects that treating physicians derive their opinions from firsthand patient interactions, rather than being engaged as independent expert consultants.


When Does a Treating Physician Need to Provide an Expert Report?

While treating physicians generally do not need to provide a full expert report, there are exceptions.

Scenarios Where a Report is NOT Required

  • The physician testifies only about diagnoses, treatment, and medical history based on their patient care.
  • The testimony is limited to observations made during treatment.

Scenarios Where a Report IS Required

  • The physician reviews outside materials (such as expert reports, depositions, or additional medical records not used in treatment).
  • They offer opinions on causation or future medical treatment that go beyond the treatment provided.
  • They extrapolate conclusions not directly formed during treatment.

If a treating physician’s testimony crosses into retained expert territory, they must comply with Rule 26(a)(2)(B) and submit a formal report.


Jurisdictional Variations: Local Rules Matter

While federal rules provide a general framework, individual courts interpret them differently. Some jurisdictions require stricter disclosures for treating physicians.

Best Practice for Attorneys:

  • Review local court rules regarding expert witness disclosures.
  • Err on the side of over-disclosure to avoid exclusion of testimony.
  • Provide clear documentation summarizing the physician’s expected testimony.

Best Practices for Attorneys Handling Treating Physician Testimony

To ensure a treating physician’s testimony is admissible and effective:

1. Clarify Their Role Early
Determine whether the physician will provide only factual testimony or offer opinions beyond direct treatment.

2. Provide Proper Disclosures
Even if an expert report is not required, prepare a thorough disclosure under Rule 26(a)(2)(C).

3. Avoid Using Non-Treatment Information
Keep testimony within the scope of the treating relationship to prevent reclassification as a retained expert.

4. Prepare the Physician for Depositions
Ensure they understand their role and avoid making speculative statements outside their expertise.

5. Consult Local Rules
Since courts vary in interpretation, check the jurisdiction’s specific rules to avoid surprises.


Expert Disclosure Requirements – Retained vs. Non-Retained Experts

Federal disclosure rules differentiate between retained experts (hired for litigation) and non-retained experts (such as treating physicians). Here's a breakdown of their respective disclosure obligations:

  • Detailed Expert Report

    • Retained Experts: Required
    • Non-Retained Experts (Treating Physicians): Not Required
  • Disclosure of Subject Matter

    • Retained Experts: Required
    • Non-Retained Experts: Required
  • Summary of Facts & Opinions

    • Retained Experts: Required
    • Non-Retained Experts: Required
  • Expert’s Qualifications

    • Retained Experts: Required
    • Non-Retained Experts: Not Required
  • List of Prior Testimonies

    • Retained Experts: Required
    • Non-Retained Experts: Not Required
  • Compensation Details

    • Retained Experts: Required
    • Non-Retained Experts: Not Required

Why This Matters:
Understanding these differences helps ensure compliance with FRCP 26, preventing the exclusion of testimony and avoiding potential delays in litigation.


Frequently Asked Questions (FAQs)

1. Can a treating physician provide an opinion on causation?
Yes, but only if the opinion was formed during treatment. If the opinion is based on additional evidence outside of treatment, the physician may be reclassified as a retained expert, requiring a full report.

2. Does a treating physician need to disclose prior testimony history?
No, non-retained expert witnesses are not required to provide a list of prior testimonies. However, attorneys should still prepare for cross-examination on this topic.

3. What happens if a treating physician is mistakenly categorized?
If a physician testifies beyond their treatment role, a court may rule that they are a retained expert. Failure to submit a proper expert report can lead to the testimony being excluded.

4. Can treating physicians testify about future medical costs?
Only if the opinions were developed during the treatment period. If the physician calculates long-term costs based on factors outside of treatment, they may need to submit an expert report.

5. What are the risks of insufficient disclosure?
If disclosures are too vague, opposing counsel may file a motion to exclude testimony. This can weaken a case significantly.

6. Are there state-specific differences in disclosure requirements?
Yes, some states have stricter disclosure requirements than the federal standard. Attorneys should consult local court rules to ensure compliance.

7. Can a treating physician refuse to testify?
Yes, unless subpoenaed. A treating physician may refuse to voluntarily testify, and in such cases, attorneys may need to issue a subpoena.


Conclusion

Treating physicians play a vital role in litigation, but their classification as non-retained experts limits their disclosure requirements. While they generally do not need to provide an expert report, their testimony must stay within the scope of treatment to maintain this status.

Attorneys must carefully navigate expert disclosure rules, ensuring compliance to avoid unnecessary legal disputes.


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