The #1 Reason Serious Injury MSJs Get Reversed

You win the serious injury MSJ at Supreme Court. The insurer is satisfied. Then the Appellate Division reverses, and reading the opinion, you realize the loss was entirely avoidable.

In a review of over 30 recent NY appellate and trial court decisions on Insurance Law 5102(d) motions from the past year, one defense error appeared more than any other: failing to address the plaintiff's claim that the accident exacerbated preexisting conditions. Seven reversals in the dataset turn on this identical mistake. The defense expert says "degenerative" and stops there, never opining on whether the accident made those preexisting conditions worse.

The fix is straightforward. But it requires knowing what the courts actually demand.

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The Rule: "Degenerative" Is Not Enough

The law is well settled. When a plaintiff's bill of particulars claims the accident exacerbated preexisting injuries, the defense cannot meet its prima facie burden simply by showing that preexisting conditions exist. The defense must go further and establish that the accident did not worsen those conditions.

This principle traces back to the Court of Appeals. In Pommells v. Perez, 4 NY3d 566 (2005), the Court held that "additional contributory factors" like preexisting conditions, gaps in treatment, and intervening medical problems can interrupt the chain of causation. But in Brown v. Dunlap, decided in the same opinion, the Court reversed summary dismissal where the defense's only evidence of a preexisting condition was a radiologist's conclusory notation that findings were "chronic and degenerative in origin," holding it insufficient to establish that the plaintiff's injuries were preexisting and unrelated to the accident. The appellate courts have applied this consistently. As the Fourth Department put it in Zazulak v. Sarna (Nov. 2025), the defense "failed to submit evidence establishing as a matter of law that the injuries were entirely [preexisting] . . . and were not exacerbated by the accident in question." That formulation — entirely preexisting and not exacerbated — is the standard the defense must clear.

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The Reversal Pattern

The same fact pattern repeats across departments. The defense expert reviews records, identifies degenerative findings, and concludes the plaintiff's conditions are preexisting. But the BOP claims exacerbation, and the expert never addresses it. Motion denied.

Paulson v. Irmgard (2d Dept, Sept. 2025) — The defendant met his prima facie burden on seriousness (that is, the experts' ROM findings were sufficient to show no significant or permanent limitation). But the defense experts "opined that the plaintiff's injuries were degenerative in nature" without addressing "the plaintiff's claims, set forth in the bill of particulars, that the accident exacerbated preexisting injuries to the cervical and lumbar regions of her spine." The Second Department reversed.

Petric v. Retsina Cab Corp. (2d Dept, Feb. 2025) — The defendants established prima facie that the plaintiff did not sustain a serious injury under the permanent consequential and significant limitation categories. But their submissions "failed to address the plaintiff's claims, set forth in the bill of particulars, that, as a result of the defendants' negligence, the accident exacerbated preexisting injuries to the cervical and lumbar regions of his spine." Reversed.

Zazulak v. Sarna (4th Dept, Nov. 2025) — Particularly instructive because the defense's own submissions created the problem. The defense submitted excerpts of the plaintiff's deposition taken three years after the accident, and those excerpts raised triable issues on whether the plaintiff's symptoms were of lengthy duration and he continued to suffer from accident-related injuries. Separately, the defense failed to establish that the plaintiff's injuries were entirely preexisting and not exacerbated by the accident. The defense lost on significant limitation and permanent consequential limitation, though it won separately on the 90/180-day category.

Holliday v. City of New Rochelle (2d Dept, Nov. 2025) — The defense met its prima facie burden on seriousness across all three categories. But the court found the defendants' submissions "failed to eliminate all triable issues of fact as to whether, as a result of the defendants' negligence, the accident exacerbated preexisting injuries to the cervical and lumbar regions of the plaintiff's spine." Reversed.

DelGrosso v. Ljutich (2d Dept, Oct. 2025) — The defendant's submissions failed to address the plaintiff's BOP claim that the accident exacerbated preexisting injuries to his left knee. Motion denied "without regard to the sufficiency of the plaintiff's submissions in opposition."

Totaro v. Malinowski (4th Dept, May 2025) and Prado v. Town/Village of Harrison (2d Dept, Dec. 2025) follow the same pattern. In each case, the defense failed to establish that preexisting injuries "were not exacerbated by the accident." Motion denied.

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The Cascading Failure: You Lose the Gap-in-Treatment Argument Too

This is where the error compounds. Under established law, when the defense fails to establish causation (which includes failing to address exacerbation), the burden never shifts to the plaintiff. That means the plaintiff does not need to explain any gap in treatment, no matter how long it is. And even when the burden does shift, the Court of Appeals set a low bar in Ramkumar v. Grand Style Transp. Enters. Inc., 22 NY3d 905 (2013): the plaintiff's deposition testimony that his no-fault benefits had been cut off was sufficient — demanding documentary proof was "an unwarranted expansion of Pommells."

Petric stated the rule explicitly: "Since the defendants failed to establish that the alleged injuries to the cervical and lumbar regions of the plaintiff's spine were not caused by the accident, the burden never shifted to the plaintiff to explain any gap in treatment."

Holliday applied the same principle: the burden "did not shift to the plaintiff to raise a triable issue of fact as to causation or to explain any gap in treatment."

And De Vito v. Grossmann (2d Dept, July 2025) made the sequencing rule unmistakable: the gap-in-treatment doctrine only applies after the defense has properly shifted the burden by establishing its prima facie case on causation. If the defense never proves lack of causation, the plaintiff need not explain any gap.

One missing paragraph in the IME report costs you two arguments.

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How to Get It Right: The Defense Wins

Not every preexisting-condition case ends in reversal. When the defense addresses exacerbation head-on, the results are decisive.

Fernandez v. Sukhdeep (1st Dept, Jan. 2026) — The gold standard. The plaintiff had a prior 2013 accident with cervical and lumbar injuries. The defense experts (a neurologist and an orthopedist) reviewed and compared the actual MRI films from 2013 and 2021, demonstrating that the post-accident studies showed only "normal progression of conditions that were already at least partially degenerative in 2013."

The burden shifted to the plaintiff, who couldn't meet it. The First Department held:

"Plaintiff was required to, and failed to, explain why the 2020 accident, and not the preexisting conditions depicted in plaintiff's own records, was the cause of his cervical and lumbar spine symptoms and limitations."

The plaintiff's only evidence on causation was his own "subjective belief" that he had recovered from the prior accident. His physicians' opinions fared no better:

"[H]is physicians' conclusory opinions as to a causal relationship, made without any acknowledgement of the prior accident or review of the records from that accident, were insufficient to raise an issue of fact."

Complaint dismissed.

Esteban v. Dubuisson (2d Dept, Aug. 2025) — The defense established that the plaintiff's left knee and cervical/lumbar spine injuries were "degenerative, preexisting, and not caused by the accident." In opposition, the plaintiff's expert failed to address the defense experts' findings of degeneration and lack of causal connection. The plaintiff then moved to renew with an amended expert report. Denied:

"A motion for leave to renew is not a second chance freely given to parties who have not exercised due diligence in making their first factual presentation."

The lesson: when the defense does the work up front, a plaintiff who submits a deficient expert report in opposition cannot get a second bite at the apple.

Krmic v. Corrie (1st Dept, Feb. 2025) — The defense submitted a radiologist's opinion that post-collision CT and MRI findings (osteophyte disc complexes, spondylosis) were degenerative and preexisting, and a neurologist who concluded that any sprain/strain occurred in the setting of preexisting degenerative disc disease. Critically, the plaintiff's own treating orthopedist's records showed near-normal cervical ROM in the months after the collision.

The plaintiff's opposing expert examined the plaintiff once, six years after the collision. The court found this examination "was too remote in time to raise an inference that any limitations were causally related to the collision," noting that the expert "failed to reconcile his current findings of limitations with plaintiff's treating orthopedist's findings of near normal range of motion in the months after the collision."

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What the Winning IME Reports Have in Common

The difference between the wins and the losses comes down to what the IME report says — or doesn't say. Here is what the successful defense reports included:

1. They started with the BOP. If the BOP claimed exacerbation, the report addressed it directly, not as an afterthought, but as a core opinion.

2. They reviewed and compared pre- and post-accident imaging. In Fernandez, the defense experts compared the actual MRI films from both accidents side by side. In Krmic, the defense radiologist reviewed the post-collision CT and MRI and tied findings to preexisting degeneration. This is the strongest evidence.

3. They didn't stop at "degenerative." Each winning report specifically opined that the accident did not cause or worsen the preexisting conditions, and explained why, tied to the imaging comparison.

4. They accounted for their own findings. In Zazulak, the defense's own deposition excerpts raised triable issues on exacerbation. Review your own submissions before filing. If anything in the IME report, deposition testimony, or medical records you're submitting suggests the accident could have worsened a preexisting condition, the motion is in jeopardy.

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Bottom Line

This is the most avoidable error in 5102(d) practice. Across all four Appellate Departments, the rule is the same: if the BOP claims exacerbation and the defense expert doesn't address it, the motion fails, regardless of how strong the rest of the submission is.

The difference between an affirmed win and a reversed loss often comes down to a single paragraph in the IME report. The law isn't working against you. The reports are.