Treating Physician vs. IME: Whose Medical Opinion the Jury Hears

In a serious maritime injury case, two very different kinds of doctors usually testify about the same body. One is the treating physician — the surgeon, the physiatrist, the psychologist who actually cared for the injured worker over weeks or months. The other is the defense's independent medical examiner (IME) — a physician hired by the employer or its insurer who examines the worker once, often briefly, for the purpose of litigation. How a jury weighs those two voices frequently decides the damages in a case.

This page explains the difference between them, the rules that govern when each can testify, and why the distinction matters.

Two roles, two purposes

A treating physician sees the patient to treat the patient. The diagnosis, the imaging, the surgical decisions, the prognosis, and the opinions about what caused the condition all arise from the course of care. That clinical record exists whether or not a lawsuit is ever filed.

An IME physician examines the worker for the litigation. In federal court the mechanism is Federal Rule of Civil Procedure 35, which allows a party to obtain a physical or mental examination of a person whose condition is in controversy, on a showing of good cause. The IME is, by design, a retained expert engaged by the opposing side.

That difference in purpose is something a jury can hear and weigh: the physician who managed the patient's care over time versus the physician who saw the patient once, at the defense's request, with an eye toward the case.

The Rule 26 report question for treating physicians

A recurring procedural issue is whether a treating physician must serve the full written expert report required of retained experts under Federal Rule of Civil Procedure 26(a)(2)(B). The general framework: a treating physician who testifies to opinions formed during the course of treatment — diagnosis, treatment rendered, prognosis — is ordinarily treated as a non-retained expert and may be disclosed under the lighter Rule 26(a)(2)(C) summary, without a full report. But when a treating physician is asked to go beyond the treatment — for example, to offer causation opinions developed specifically for the litigation or based on materials reviewed only for the case — some courts require the full report and may limit testimony that exceeds the treatment relationship.

Courts are not perfectly uniform on where that line falls, and the consequences of getting the disclosure wrong can be severe: a missing or inadequate disclosure can lead to exclusion of the opinion. Proper, timely disclosure of treating physicians — and careful framing of the scope of their opinions — is one of the quieter but more important pieces of preparing an injury case.

Admissibility still runs through Daubert

Whichever side calls the witness, expert medical testimony must satisfy Federal Rule of Evidence 702 and the reliability standard of Daubert v. Merrell Dow Pharmaceuticals. The opinion must rest on sufficient facts or data, be the product of reliable principles and methods, and reflect a reliable application of those methods to the facts. A treating physician's causation opinion is not automatically admissible simply because the physician provided care; it must still be reliable. By the same token, an IME's opinion is not insulated from challenge — a one-time examination that ignores the treatment record or rests on conclusory reasoning can be attacked on the same reliability grounds.

Why the treating relationship carries weight

When the medical opinions are properly developed and admitted, the treating physician often carries persuasive advantages that no amount of credentials can fully offset. The treating doctor watched the condition unfold, made decisions with real consequences for the patient, and has no stake in the outcome of the lawsuit. The IME, by contrast, is paid by the defense and saw the worker once. Juries notice that difference — particularly when the treating physician's contemporaneous records line up with the worker's account and the IME's conclusions do not.

The role of the treating physician was central to the damages proof in Gillies v. Valaris: a treating orthopaedic surgeon documented an unresolved sacroiliac joint injury, and a treating psychologist diagnosed the post-traumatic stress that followed the loss of a long career. Testimony anchored in the actual course of care — supported by family witnesses who described the change in the man himself — is what made a "non-surgical" injury read to the jury as the serious, lasting harm it was.

The practical point

For an injured worker, two things follow. First, keep treating — a consistent course of care with physicians the worker chose builds the record that supports the case, and gaps in treatment are something the defense will exploit. Second, understand that a defense IME is not a neutral referee; it is a litigation tool, and its conclusions can be tested and cross-examined like any other retained opinion.

For related reading, see the Jones Act and maintenance and cure, which governs the seaman's right to medical care during recovery.

In practice

In practice, the defense's paid independent medical exam exists to manufacture a 'you're fine' opinion to set against the physicians who actually treat you. The fight is over admissibility and weight, and a one-time, litigation-driven exam rarely outweighs a consistent, contemporaneous treating record built over months of care.