In Ontario, every employer — regardless of size — owes a mutual duty to cooperate in an injured worker's return to work under WSIA s. 40, and must file Form 7 within 3 business days (WSIA s. 21). Employers with 20 or more workers also owe a re-employment obligation under WSIA s. 41 once the worker has at least 1 year of service: they must keep the worker's job (or a comparable one) available until the earliest of 2 years from the date of injury, 1 year after the worker is medically able to do the pre-injury job, or the worker's 65th birthday. Failing to re-employ can cost up to the worker's net average earnings for one year; failing to report the injury is an offence under WSIA s. 152 (penalty under s. 158: a fine up to $25,000 for an individual or $500,000 for a corporation on conviction).
Ontario's return-to-work (RTW) obligations are set out in sections 40 and 41 of the Workplace Safety and Insurance Act, 1997 (WSIA). These are not suggestions or best practices — they are statutory obligations enforced by WSIB with financial penalties for non-compliance. Every employer who has a worker injured on the job needs to understand these rules. So does the injured worker.
Section 40 of the WSIA creates a mutual obligation. The employer must cooperate in the return-to-work process, and so must the worker. This is not optional for either party. For employers with 20 or more workers, s.40 triggers the full suite of re-employment obligations: contact the worker within three days, identify suitable modified work, make a written offer, and cooperate with WSIB throughout the process. For employers with fewer than 20 workers, the formal re-employment obligation under s.40 does not apply — but the duty to cooperate still does, and the Ontario Human Rights Code requires accommodation to the point of undue hardship regardless of company size. The worker's obligations are equally clear: cooperate in the return-to-work effort, accept suitable modified work when it is offered, provide functional abilities information to the employer, attend medical appointments, and communicate any changes in condition. A worker who refuses suitable modified work without good reason risks having their Loss of Earnings benefits reduced or suspended by WSIB. The system is designed to get injured workers back to productive, safe work as quickly as their medical condition allows — not to warehouse people on benefits indefinitely, and not to let employers ignore their injured workers.
The Functional Abilities Form (FAF) is the single most important document in the return-to-work process. It is completed by the worker's treating physician and describes, in specific functional terms, what the worker can and cannot do. Not diagnoses, not prognoses — functional abilities. Can the worker lift 10 pounds? Stand for 30 minutes? Use both hands? Climb stairs? The employer uses the FAF to design a modified work offer that fits within the worker's actual capabilities. Without the FAF, the employer is guessing — and guessing leads to re-injury, disputes, and WSIB penalties. The employer provides the blank FAF to the worker, who takes it to their next medical appointment. The treating physician completes it based on their clinical assessment. The completed form comes back to the employer. If the worker's condition changes — improves or worsens — a new FAF should be obtained. The FAF is not a one-time document; it evolves with the worker's recovery. Employers who fail to request the FAF, or who ignore the restrictions it sets out, are setting themselves up for a duty-to-accommodate failure. Workers who fail to get the FAF completed, or who misrepresent their abilities, are breaching their duty to cooperate.
Modified work is real, productive work that has been adjusted to fit within the injured worker's functional abilities. It is not make-work. It is not sitting in a break room watching safety videos for eight hours. It is not the same job with a vague instruction to "take it easy." Modified work must be meaningful, must be within the worker's documented abilities (per the FAF), and must be available at the worker's regular workplace whenever possible. Examples of genuine modified work: a framing carpenter with a back injury who cannot lift more than 20 pounds is assigned to layout, measuring, and cutting light materials. A warehouse worker with a knee injury who cannot stand for more than 30 minutes at a time is assigned to seated inventory data entry. A roofer with a fractured wrist is assigned to ground-level material staging with one-hand tasks. The key is matching the work to the worker's abilities — not the other way around. The employer cannot simply say "we have no modified work available" without documenting a genuine assessment of all available tasks. WSIB expects employers to look creatively at the full range of work in their operation. If truly no modified work exists — which is rare in any business with more than a handful of employees — the employer must document what was considered and why it was not feasible.
Section 41 of the WSIA imposes a specific re-employment obligation on employers with 20 or more workers. When the worker is medically able to perform the essential duties of their pre-injury job, the employer must offer that job back. If the worker cannot do the pre-injury job but can do other work, the employer must offer the first suitable alternative that becomes available. The employer must keep the position available (or a comparable one) until the earliest of: two years after the date of injury; one year after the worker becomes medically able to perform the essential duties of the pre-injury job; or the worker's 65th birthday. This is an enforceable obligation. If the employer fails to re-employ the worker, WSIB can impose a penalty of up to the worker's net average earnings for one year — which can amount to tens of thousands of dollars — plus continued claim costs on the employer's account. The employer must also not punish the worker for filing a claim. Dismissing a re-employed worker within six months of re-employment is presumed (rebuttably) to breach the re-employment duty under s. 41(10), and WSIB can order reinstatement plus the net-average-earnings penalty. Discouraging or suppressing a worker's claim is a separate offence under WSIA s. 155.1 (contravening the s. 22.1 prohibition), punishable under s. 158 on conviction by a fine up to $25,000 for an individual or $500,000 for a corporation.
Maximum Medical Recovery is the point where the worker's condition has plateaued — further improvement is not expected even with continued treatment. This is a medical determination, not an administrative one. When the treating physician or a WSIB-appointed physician determines the worker has reached MMR, several things happen. First, WSIB conducts a permanent impairment assessment. If a permanent impairment is found, the worker receives a Non-Economic Loss (NEL) award — a lump sum payment based on the type and degree of impairment, as rated on the American Medical Association Guides to the Evaluation of Permanent Impairment. NEL awards can range from a few thousand dollars for minor impairments to over $100,000 for severe ones. Second, the worker's Loss of Earnings (LOE) benefit is reviewed. LOE pays 85% of the difference between the worker's pre-injury earnings and their post-injury earnings (or earning capacity). If the worker has returned to work at full wages, LOE stops. If the worker is earning less, LOE continues. If the worker cannot return to their pre-injury employer at all, WSIB may fund Work Transition services — vocational assessment, retraining, and job search assistance to help the worker find new employment that matches their residual abilities. LOE benefits are subject to a major review at the 72-month mark, where WSIB may deem the worker capable of earning a certain amount based on their transferable skills and local labour market, regardless of whether they are actually employed.
Non-compliance with RTW obligations is expensive for both sides. For employers: WSIB can impose financial penalties, charge the full cost of the claim to the employer's account (affecting experience rating and premiums for years), and order reinstatement of a worker who was wrongfully terminated. A single lost-time claim that drags on because the employer failed to offer modified work can cost tens of thousands in benefits charged to the employer's account, plus the penalty for non-compliance, plus increased premiums in future years. For workers: WSIB can reduce or suspend LOE benefits if the worker refuses suitable modified work or fails to cooperate with the RTW process. A worker who does not attend medical appointments, does not provide functional abilities information, or refuses a reasonable modified work offer is breaching their duty to cooperate under s.40. WSIB does not need court approval to reduce benefits — it is an administrative decision. The worker can appeal, but benefits may be reduced while the appeal is pending. The incentive structure is clear: both parties benefit from early, genuine return-to-work efforts. The employer avoids escalating claim costs. The worker returns to productive employment and income. WSIB's research consistently shows that the longer a worker is away from work, the less likely they are to ever return. Early and sustained contact, genuine modified work offers, and progressive increases in duties are the keys to a successful return-to-work outcome.
Return-to-work paperwork is only as good as the records behind it. If you run crews in Ontario, ToolFluency's Ontario contractor suite keeps timesheets, injury dates, and job records in one place, so a Form 7 deadline or a modified-work log never has to be reconstructed from memory. For more Ontario safety and WSIB calculators — first aid, premiums, critical-injury reporting — see the WSIB & OHSA tools hub.
The Workplace Safety and Insurance Act s. 40 imposes a mutual duty on the employer and the injured worker to cooperate in the worker's early and safe return to work. The employer must contact the worker promptly after injury, maintain communication, identify suitable modified work, and provide it.
By the ToolFluency team · Updated September 2026
Free interactive guide for WSIB return-to-work obligations in Ontario. Select your role, injury type, and stage to see your obligations under WSIA section 40 — modified work, timelines, forms, checklists, and consequences of non-compliance.
Part of ToolFluency’s library of free online tools for WSIB & OHSA. No account needed, no data leaves your device.