The CNESST issues a written decision after reviewing a claim for a work accident or an occupational disease. This process begins with the first steps to take after a work accident and, in some cases, extends to the CNESST’s handling of an occupational disease. If the decision is unsatisfactory, it can be contested through administrative review, through reconsideration or, since April 2023, directly before the Administrative Labor Tribunal (Tribunal administratif du travail, or TAT). Meeting the legal deadlines is critical: an appeal filed late may be dismissed, regardless of the merits of the case.
Attorney Bégin, a work accident lawyer, explains the remedies available, the applicable deadlines, and the factors that genuinely influence the chances of success of a contestation.
Key Takeaways
- A CNESST decision can be contested through administrative review (30 days) or, since April 2023, directly before the TAT (60 days).
- The deadline to contest an administrative review decision before the TAT is 60 days, no longer 45 days, since the reform of April 6, 2023.
- If the CNESST does not respond to a review request within 90 days, the case can be brought directly before the TAT without waiting.
- The number of contestations filed with the TAT has risen steadily over the past ten years, which makes mastery of deadlines and procedure even more important.
What to do once the CNESST has issued its decision
Three distinct remedies exist to contest a CNESST decision: administrative review, reconsideration and, since the 2023 reform, direct contestation before the TAT. The choice of remedy depends on the type of decision, the time remaining and the strategy adopted.
1. Administrative Review
Administrative review asks the CNESST’s Administrative Review Branch (Direction de la révision administrative) to verify whether the file was handled in accordance with the applicable standards and policies. The form, available on the CNESST website, must set out the grounds for the contestation, along with the file number and a copy of the decision at issue.
The deadline to submit this request is 30 days from receipt of the initial decision. The CNESST then has 90 days to issue its new decision. If it has not responded within that period, the worker may contest directly before the TAT without waiting for a response.
2. Reconsideration of a Decision
Reconsideration allows the CNESST to rule a second time in order to correct an error or to take into account an essential fact that was unknown when the first decision was made. It may be requested by the worker within 90 days, or initiated by the CNESST itself.
This remedy is used less often than administrative review, but it remains relevant when a specific factual error is at issue rather than a general disagreement with the assessment of the file.
3. Direct Contestation Before the Administrative Labor Tribunal
Since the reform took effect on April 6, 2023, it is no longer mandatory to go through administrative review before turning to the TAT. A person who believes they have been wronged may choose to contest the CNESST decision directly before the TAT, within 60 days.
This choice has an important consequence: opting for direct contestation before the TAT means giving up the possibility of requesting reconsideration of that same decision. The strategy adopted (review, reconsideration or direct TAT contestation) must therefore be assessed before acting, not afterward.
What are the deadlines to contest a CNESST decision?
The applicable deadlines vary depending on the type of decision and the remedy chosen, and they were substantially modified by the 2023 reform. The following table summarizes the deadlines currently in effect.
| Type of Remedy | Deadline | Competent Authority |
| Request for administrative review | 30 days | CNESST, Administrative Review Branch |
| CNESST response to a review request | 90 days | CNESST |
| Contestation of a decision rendered on review | 60 days | TAT |
| Direct contestation (without prior review) | 60 days | TAT |
| Request for reconsideration | 90 days | CNESST |
| Preventive withdrawal, right to refuse, reassignment to other duties | 10 days | CNESST |
This last category is an exception: for a contestation relating to eligibility for preventive withdrawal, the right to refuse unsafe work, or reassignment to other duties, the deadline remains 10 days. It is advisable to contest a decision as soon as possible, even when the chances of success are uncertain, in order to preserve one’s rights.
Temporary assignment
A temporary assignment may be contested, regardless of the opinion of the treating health professional, if the worker believes they are unable to perform the assigned tasks, if those tasks pose a danger to their health, or if they interfere with their rehabilitation.
What Is the procedure for contesting a temporary assignment?
The request must be submitted to the company’s occupational health and safety committee or, in the absence of such a committee, to the prevention representative and the employer. The decision is rendered after consultation with the physician responsible for the company’s health services or, failing that, the regional public health director.
If there is no committee or prevention representative, the request may be sent directly to the CNESST regional office, which renders its decision within 20 days.
What factors influence the chances of success of a contestation?
No contestation can be accompanied by a promise of results, but certain concrete factors objectively strengthen a case. The quality of the medical evidence, strict compliance with deadlines and the clarity of the written argument are the three most decisive factors in the handling of a review or contestation.
- Medical evidence: complete, consistent and up-to-date reports from the treating physician form the foundation of any solid case. A medical report after a work accident can reinforce this evidence when the CNESST challenges the conclusions in the file.
- Compliance with deadlines: the TAT may raise a missed contestation deadline on its own initiative, even if the merits of the case are well supported.
- Precision of the argument: clearly setting out the grounds for disagreement with the initial decision, rather than offering generalities, facilitates the analysis of the file.
- Choice of remedy: administrative review, reconsideration and direct contestation before the TAT do not follow the same logic or the same timeline.
The number of cases opened at the Administrative Labor Tribunal rose by 44% between 2013-2014 and 2021-2022, and the increase has continued since. This growth illustrates the value of being assisted by an administrative law lawyer as soon as a decision is received, rather than waiting for the deadlines to expire.
Bégin Avocat supports you in contesting a CNESST decision
A CNESST decision considered unsatisfactory can be contested, but each remedy is subject to precise deadlines and its own logic. A prompt assessment of the file makes it possible to choose the most appropriate path, whether administrative review, reconsideration or direct contestation before the TAT.
Attorney Bégin assists workers throughout these proceedings, from the initial analysis of the decision to representation before the TAT. To assess a specific situation, you may fill out the contact form or call the firm at 514 509-7852.
Your questions about contesting and reviewing a CNESST decision
What is the deadline to contest a CNESST decision before the Administrative Labor Tribunal?
The deadline is 60 days from notification of the decision. This deadline increased from 45 to 60 days following the reform that took effect on April 6, 2023.
How long does the CNESST have to respond to an administrative review request?
The CNESST has 90 days from receipt of the complete file to render its decision. After that period, it is possible to contest directly before the TAT without waiting.
Is it mandatory to go through administrative review before turning to the TAT?
No. Since April 2023, it is possible to choose between administrative review and direct contestation before the TAT, within 60 days of the decision.
What is the difference between administrative review and reconsideration?
Administrative review verifies whether the file was handled in accordance with the applicable standards. Reconsideration corrects a specific error or takes into account a new fact that was unknown when the initial decision was made.
What is the deadline to request reconsideration of a CNESST decision?
The deadline is 90 days from notification of the decision at issue.
What factors increase the chances of success of a contestation?
The quality of the medical evidence, strict compliance with deadlines and the clarity of the written argument are decisive, although no result can be guaranteed.
What happens if the contestation deadline has passed?
The TAT may raise the missed deadline on its own initiative. A reasonable explanation for the delay may be presented, but there is no guarantee it will be accepted.
Can a decision concerning a temporary assignment be contested?
Yes, within 10 days, by first applying to the company’s health and safety committee or, failing that, to the CNESST regional office.