New Jersey law requires that trial courts conduct a “rigorous gatekeeping” analysis when assessing the admissibility of expert opinions.  That’s the Accutane standard, named for the New Jersey Supreme Court’s opinion in In re Accutane, 234 N.J. 340 (2018).  To the extent there was any ambiguity on whether Accutane applies to all civil cases, the New Jersey Supreme Court has now revolved it  Accutane applies in every civil case.  Moreover, the “rigorous analysis” requirement applies to all purported methodologies, including differential diagnoses.

The case is Beavan v. Allergan U.S.A., Inc., 355 A.3d 1201 (N.J. 2026), which involved an FDA-approved steroid pellet used to treat certain eye conditions. In 2018, the manufacturer advised the FDA that during assembly a tiny silicone particulate could detach from the needle’s sleeve and be ejected with the pellet.  This issue ultimately led to a recall covering twenty-two lots in which sample testing showed that two of ninety units—2.2 percent—contained a silicone particulate.

The plaintiff was treated with an injection from a recalled lot and alleged that she lost vision in one eye as a result.  To prove this, she relied on two experts, whose opinions were based on . . . well, not much.  Both reasoned that because the plaintiff had received prior injections without complications, the recalled unit must have been defective and most likely caused the injury.  But notably, neither could cite evidence that a silicone particulate was actually generated or injected during the plaintiff’s procedure.  As one expert (the treating physician) acknowledged, “the only thing we were going by” was that “it was a recalled lot.”  Beavan, 355 A.3d at 1210. 

The trial court found these opinions sufficiently reliable to raise triable issues of fact, but did so without conducting the Accutane gatekeeping inquiry.  The Appellate Division reversed and ordered entry of summary judgment for the defendant, in an opinion that we reported on here. 

The New Jersey Supreme Court took a different tack and remanded for the trial court to conduct the proper “rigorous gatekeeping” under Accutane.  According to the Supreme Court any dispute about the reliability of expert testimony in a civil case must be resolved by the trial court acting as gatekeeper, applying the Accutane framework.  Here is the quote you will want to use:

Our view of proper gatekeeping in a methodology-based approach to reliability for expert scientific testimony requires the proponent to demonstrate that the expert applies . . . scientifically recognized methodology in the way that others in the field practice the methodology. When a proponent does not demonstrate the soundness of a methodology, both in terms of its approach to reasoning and to its use of data, from the perspective of others within the relevant scientific community, the gatekeeper should exclude the proposed expert testimony on the basis that it is unreliable.

Beavan, 355 A.3d at 1216 (quoting Accutane).  There are no exceptions.  Nor is Accutane’s mandate confined to the mass tort context, which the Supreme Court made clear:

The procedural framework adopted in Accutane is not limited to the specific setting in which that case arose; it applies to all civil cases in which the parties dispute the reliability of expert testimony under N.J.R.E. 702 and 703.

Id. (emphasis added). 

Accutane likewise carved out no exception for differential diagnosis. To the contrary, when an expert uses a differential diagnosis to opine on the cause of an injury, the gatekeeping inquiry must be applied to both steps of the analysis: the “rule in” step, in which the expert compiles plausible causes, and the “rule out” step, where the expert eliminates factors to reach a conclusion as the most likely cause. The trial court must scrutinize each component of the opinion to confirm it rests on a methodology satisfying Accutane.

Applying these principles, the Supreme Court held that the trial court erred by admitting the testimony without “rigorous gatekeeping,” and the Appellate Division got it wrong too by directing entry of summary judgment.  The proper outcome, in the Supreme Court’s view, was to remand for the trial court to properly assess the admissibility of plaintiffs’ experts.

So the plaintiff gets a do over.  The Supreme Court encouraged the trial court to hold an evidentiary hearing, and it also held that the plaintiff’s retained expert’s opinion was not a “net opinion,” which is a New Jersey thing.  A “net opinion” is one that is unsupported by facts or data, but the retained expert here adequately explained the “why and wherefore” of his opinions in his report.  That does not, however, mean that the retained expert’s opinions will be admissible after scrutiny under Accutane, which is a separate inquiry. 

Finally, the Court also flagged that a treating physician designated to offer expert causation testimony must, like a retained expert, serve a written report when an adversary requests one through interrogatories. The treating physician here did not prepare a report.  On remand, the trial court will determine whether the plaintiff will be allowed to serve one. 

The New Jersey Supreme Court vacated a good outcome for the defendant in the Appellate Division, but the good news is that it solidified the trial court’s gatekeeping role and closed off any uncertainty on whether and how broadly Accutane applies.  Rigorous gatekeeping is required, in all civil cases.