Catastrophic Impairment in Ontario: Why One Unsourced Definition Can Cost You $1 Million in Benefits

On a warm afternoon in September 2026, Vice-Chair Craig Mazerolle of Ontario's Licence Appeal Tribunal released a reconsideration decision that would ripple through the province's personal injury bar. The case, Intact Insurance Company, 2026 CanLII 94563 (ON LAT), involved a woman injured in a July 2020 car crash. After a four-day hearing, she was told her injuries did not add up to catastrophic impairment, the designation that unlocks Ontario's most extensive accident benefits.

Her combined impairment score came in at 50 percent. The threshold is 55.

The difference between those two numbers is not abstract. It is the difference between $65,000 in medical and rehabilitation benefits and $1 million over a lifetime. It is the difference between a system that offers a measure of support and one that offers a genuine path to recovery.

Mazerolle cancelled the original decision. He ordered a new hearing before a different adjudicator, working from the same transcripts and exhibits. The reason he gave should concern every injured Ontarian who has ever navigated the accident benefits system.

The Nystagmus Problem

The disputed finding involved vertigo. The claimant's neurologist believed she had nystagmus, an involuntary eye movement, and scored that impairment at 7 percent. The original adjudicator rejected the diagnosis, but leaned on a detailed technical description of the condition that appeared in the decision from no identifiable source.

Mazerolle found that gap mattered. The definition went further than anything the neurologist himself had said in his testimony. Adjudicators can only draw on medical knowledge that is genuinely well-established and widely recognized, not a definition of their own making. That, he ruled, was an error serious enough to have changed the result.

The legal principle is straightforward, but its implications are profound. When the Licence Appeal Tribunal decides a catastrophic impairment claim, it must ground every key factual finding in the evidence actually before it. If an adjudicator uses a technical medical definition that did not come from any witness or document in the hearing, that is a legal error, not a permissible exercise of the Tribunal's specialized knowledge.

The Tribunal can only take notice of facts that are genuinely "generally recognized" within its expertise. Where an expert witness was called specifically to explain a medical term, that term is not generally recognized enough to be assumed. The presence of the neurologist's testimony made the adjudicator's reliance on an external definition inappropriate.

The Second Problem: Psychological Impairment

There was a second issue, this time over the claimant's psychological impairment score.

Her own assessor put it at 15 percent. The insurer's expert put it at 10 percent. The two agreed on one clinical scale but split sharply on two others. The original decision picked the insurer's number without explaining why, even describing the claimant's assessor's opinion as severe without saying what that meant.

Mazerolle called that a real fairness problem rather than a stylistic one. Catastrophic impairment findings carry serious consequences for claimants and insurers alike, he wrote, and deserve a clear, traceable explanation, one the original decision never gave.

The Tribunal owes a high level of procedural fairness in catastrophic impairment cases because the consequences are so significant for the injured person. That means the Tribunal must explain, clearly and in enough detail, why it preferred one expert's scoring on tools like the GAF and PIRS over another's. A decision that simply announces a preference without walking through the reasoning on the key scoring differences does not meet that standard.

Why This Case Matters for Every Injured Ontarian

Mazerolle was careful to note that reconsideration is not a chance to reargue a case just because a party dislikes how the evidence was weighed. The bar for reopening a decision stays high. Most reconsideration requests are dismissed.

But he found that accepting the claimant's numbers on vertigo and psychological impairment would have pushed her combined score over the catastrophic impairment threshold. That is what made the errors material. They were not technicalities. They were the difference between catastrophic and non-catastrophic.

The case establishes something important: accident benefit claimants can challenge a Licence Appeal Tribunal ruling when an adjudicator relies on unexplained technical definitions or fails to clearly explain why one expert's opinion was preferred over another's.

Taken together, a legal error on one impairment category and a fairness breach on another can be enough to overturn an entire catastrophic impairment ruling.

The Stakes: $65,000 vs. $1 Million

The numbers involved in this case are not abstractions. They represent the difference between a system that provides meaningful support and one that leaves injured people to fend for themselves.

Under Ontario's Statutory Accident Benefits Schedule, a non-catastrophic impairment carries a cap of $65,000 in medical and rehabilitation benefits. A catastrophic impairment designation unlocks $1 million. The 55 percent whole person impairment threshold is the gatekeeper.

For the claimant in this case, her combined score of 50 percent placed her on the wrong side of that gate. The adjudicator's errors, if uncorrected, would have cost her access to benefits that could fund years of rehabilitation, attendant care, and other supports.

This is not a unique situation. Across Ontario, injured people are navigating a system where the difference between catastrophic and non-catastrophic designation often hinges on the careful presentation and weighing of medical evidence. When that process is flawed, the consequences are measured in hundreds of thousands of dollars and, for many families, in the quality of life that those dollars can buy.

The Rehearing: What Comes Next

The Tribunal cancelled the original decision and ordered a new hearing before a different adjudicator. The rehearing will proceed on the existing hearing record, the transcript or recording and exhibits from the original proceeding, rather than starting the case over from scratch. Whoever arranged the court reporter for the original hearing now has 30 days to share a copy with both the other side and the Tribunal. Mazerolle will not be involved going forward.

The outcome of the rehearing is entirely open. The reconsideration decision establishes a procedural right to a fair, adequately reasoned decision, not a substantive right to any particular impairment rating.

But for the claimant, the door has been reopened. For other injured Ontarians facing similar battles, the case offers a roadmap for challenging decisions that rely on unexplained definitions or fail to adequately justify why one expert's opinion was preferred over another's.

What This Means for You

If you have been injured in a motor vehicle accident in Ontario and are seeking a catastrophic impairment designation, this case underscores the importance of experienced legal representation.

The process of proving catastrophic impairment is complex and adversarial. Insurers have every incentive to deny catastrophic designation, because the difference between $65,000 and $1 million is enormous. Assessments must be carefully chosen. Medical evidence must be assembled. Legal arguments must be made.

A Toronto catastrophic injury lawyer who understands the catastrophic impairment threshold can help you navigate this process, challenge insurer denials, and pursue the full benefits available under Ontario law. If your injuries involve a brain injury, a Toronto traumatic brain injury lawyer can bring specialized knowledge of the medical and legal complexities involved in ABI claims.

The Intact case shows that the system is not infallible. Adjudicators can make errors. Decisions can be flawed. But the law provides mechanisms for challenging those decisions, and with the right representation, injured Ontarians can ensure their cases are decided on the evidence, not on unsourced definitions or unexplained reasoning.

The Road Ahead

The Intact reconsideration decision is a reminder that the accident benefits system, for all its complexity, is not beyond correction. When the Tribunal makes a legal error or breaches procedural fairness, claimants have recourse.

For injured Ontarians, the message is clear: if you believe your catastrophic impairment claim was decided unfairly, do not assume the decision is final. The law provides avenues for reconsideration, and with experienced legal guidance, those avenues can lead to a different outcome.

The difference between $65,000 and $1 million in benefits is not just a number. It is the difference between a system that works for injured people and one that leaves them behind.