How to Choose a Mediator in Ontario: What Every Party Should Know
Choosing a mediator in Ontario insurance or personal injury claims isn’t straightforward. The process under s. 258.6 of the Insurance Act and Ontario Regulation 461/96 involves procedural steps that most counsel don’t use - who selects the mediator, what happens when the parties can’t agree, and the cost consequences for insurers that refuse to participate. This article walks through that procedure, the two leading decisions that govern it (Thomson v. Portelance and Keam v. Caddy), and what to look for when selecting a Ontario insurance claim mediator. Bruce Cook at Cook Reynolds in Hamilton has handled these disputes from both sides of the bar.
Last updated April 15, 2026
The Ontario Mediator Selection Impasse in Insurance Litigation
This article is written for Ontario plaintiff counsel handling mediator selection disputes in personal injury and related claims under the Insurance Act. It outlines the procedure under Ontario Regulation 461/96 that’s available when plaintiff and defence counsel can’t agree on a mediator - a procedure that exists but is rarely used.
Disputes over mediator selection in Ontario insurance litigation tend to follow a predictable path. Plaintiff counsel requests mediation under s. 258.6 of the Insurance Act and proposes experienced, specialist mediators whose qualifications are strong and whose skills match the complexity of the case. Defence counsel counters by insisting on a "roster" mediator, or at least someone willing to work at roster rates.
The disagreement usually centres on fees and qualifications. Throughout most of Ontario, there isn’t a mediation roster. The roster is a creature of Rule 24.1 of the Rules of Civil Procedure, and that rule only applies in actions commenced in Ottawa, Essex County, and Toronto. The Insurance Act and the Regulation don’t speak to specific rates - only that the insurer pay "reasonable fees and expenses." The two sides talk past each other, and the file stalls.
It doesn’t have to.
The Procedure Most Counsel Have Forgotten
There’s a mechanism to break this impasse. It’s been available since 1996, but many counsel either don’t know about it or don’t avail themselves of it. Under section 3 of Ontario Regulation 461/96 (Court Proceedings for Automobile Accidents that Occur on or after November 1, 1996), if the parties can’t agree on a mediator, each of them names a person (within 10 days) to participate in the appointment of a mediator. Those two persons together appoint the mediator. The full text of section 3 is worth setting out:
3. (1) If a request for mediation is made under subsection 258.6 (1) of the Act, the plaintiff and the defendant’s insurer shall, within 10 days after the request is made, agree on and appoint a person to be the mediator. O. Reg. 461/96, s. 3 (1).
(2) If the plaintiff and the defendant’s insurer are unable to agree on the appointment of a mediator, each of them shall, within 10 days after the request is made, name a person to participate in the mediator’s appointment, and the two persons named shall together appoint a person to be the mediator. O. Reg. 461/96, s. 3 (2).
(3) The mediation shall begin on a date agreed to by the plaintiff and the defendant’s insurer or, if they are unable to agree on a date, within 14 days after the mediator is appointed. O. Reg. 461/96, s. 3 (3).
(4) The mediator may adjourn the mediation, with or without conditions,
(a) if the plaintiff or the defendant’s insurer is represented in the mediation and the representative is not authorized to bind the person he or she represents; or
(b) the plaintiff or defendant is not present at the mediation. O. Reg. 461/96, s. 3 (4).
(5) The mediator shall give the plaintiff and the defendant’s insurer a written report identifying the issues that were settled and the issues that remain in dispute. O. Reg. 461/96, s. 3 (5).
(6) The defendant’s insurer shall pay all reasonable fees and expenses of the mediator. O. Reg. 461/96, s. 3 (6).
In the 2018 decision of Thomson v. Portelance 2018 ONSC 1278, Justice Stephen Firestone held that once plaintiff counsel requests mediation under the Insurance Act, the defendants have a positive obligation to appoint a mediator and schedule and conduct the mediation within the timeframes and procedures set forth in s. 258.6(1) of the Act and O. Reg. 461/96.
In Keam v. Caddy 2010 ONCA 565, 103 O.R. (3d) 626, the Court of Appeal held that the legislature has clearly determined that in every case where one party is willing, mediation is the best way to try to promote settlement of claims and to avoid the expense of a possibly lengthy and certainly costly trial. The legislature provided no exceptions to this policy or to the obligation that it imposed. The insurer has no option whether or not to participate. To elect not to participate constitutes a breach of the insurer’s statutory obligation.
The cost consequences of that breach follow the insurer to trial. There’s no mechanism if the case settles before trial. At paragraph 26, the Court of Appeal held:
The cost consequences will follow whether the plaintiff or the defendant has been successful at trial, so that, for example, where a plaintiff's claim is dismissed, the trial judge may deprive the winning defendant -- represented by the insurer that refused to accept a request to mediate -- of all or part of its costs that would normally follow the event.
What to Look for in a Mediator for Insurance Litigation
There’s little guidance from the courts on what "reasonable fees and expenses" means in this context. We do have some clues. The Court of Appeal in Keam suggested that the "legislature’s approach recognizes that participation in a mediation could have a salutary effect on one or both sides, with input from an experienced and respected mediator." It’s probably not sufficient to propose a mediator without extensive experience in personal injury litigation. Someone whose commentary carries weight with both counsel and the parties is what the regulation contemplates - a practitioner with a well-balanced approach and a background in both insurance defence and plaintiff personal injury matters is more likely to be effective.
The Keam decision’s reference to "an experienced and respected mediator" points to several practical criteria:
Does the mediator have substantial experience in personal injury and insurance litigation? Someone who’s spent most of their career in family law or commercial disputes isn’t likely to know the mechanics of an MVA tort claim well enough to test the assumptions on either side.
Has the mediator practiced on both sides of the bar? A mediator who’s done both plaintiff work and insurance defence work tends to carry more credibility with both counsel. They can speak to the strengths and weaknesses of each side’s position from direct experience, not theory.
Does the mediator have a history of settling comparable cases? Both counsel should be looking for someone with a record of resolving claims in the same range and complexity.
Is the mediator’s approach suited to the case? Some mediators are directive - they push the parties toward what they think the result should be. Others are facilitative - they help the parties find their own resolution. Neither is right or wrong, but the fit matters. A catastrophic injury claim with entrenched positions may need a different style than a soft tissue case where the numbers aren’t far apart.
What’s required from both sides is that they follow the process set out by the Insurance Act and the regulation. If they can’t agree on a mediator, the next step is for each side to appoint a person to participate in the selection. One can expect those persons to consider what mediator is best suited to help resolve the case at hand.
Not every personal injury matter will need the most prominent mediator in the province. But picking a mediator based on fees alone, without regard for their experience or the likelihood of resolution, isn’t reasonable either. Sometimes just raising the s. 3 procedure and having a conversation about whether it’s needed is enough to reach a compromise.
When Mediation Is Mandatory in Ontario
Ontario has two separate mediation frameworks, and confusing them causes problems in practice.
The first is Rule 24.1 of the Rules of Civil Procedure. Rule 24.1 applies to certain civil actions commenced in Toronto, Ottawa, and Essex County. Under this rule, the parties select a mediator from the local roster or choose someone outside of it. The mediation has to take place within 180 days of the first defence being filed (90 days in simplified procedure actions). Roster mediator fees are capped by O. Reg. 451/98.
The second is s. 258.6 of the Insurance Act, which applies province-wide to motor vehicle accident claims. When the plaintiff requests mediation under this section, the insurer is required to participate and to pay all reasonable fees and expenses of the mediator. There’s no roster, no fee schedule, and no geographic restriction. The process and timelines are set by O. Reg. 461/96 - the regulation discussed in this article.
These two regimes don’t overlap. An action that’s already been through mediation under s. 258.6 of the Insurance Act is exempt from mandatory mediation under Rule 24.1, provided the mediation took place less than one year before the first defence was delivered.
The distinction matters for mediator selection. Under Rule 24.1, the roster creates a natural starting point - the parties often default to whoever’s available on the list. Under the Insurance Act, there’s no list. The parties have to agree on a mediator, and if they can’t, the procedure in O. Reg. 461/96 gives each side a mechanism to break the deadlock.
Mediator vs. Arbitrator in Ontario
In Ontario legal practice, the terms "mediator" and "arbitrator" get used interchangeably more often than they should. They’re different processes with different outcomes.
A mediator is a neutral third party who helps the opposing sides reach a voluntary agreement. The mediator doesn’t decide the case or impose a result. If mediation doesn’t produce a settlement, the parties still have their right to trial. The mediator’s role is to test each side’s assumptions, identify common ground where it exists, and find out whether there’s a zone of agreement that counsel haven’t seen on their own.
An arbitrator is closer to a private judge. The arbitrator hears evidence, considers submissions, and makes a binding decision. The parties give up their right to trial in exchange for a faster, less formal process. In Ontario insurance law, arbitration comes up most often in accident benefits disputes before the Licence Appeal Tribunal (formerly FSCO). Tort claims - the kind governed by s. 258.6 of the Insurance Act - go through mediation, not arbitration.
Some practitioners do both. A mediator who can speak credibly about what a judge or arbitrator is likely to do with a particular set of facts brings something to the table that a generalist can’t. That credibility - the ability to reality-test each side’s position in a way that both counsel take seriously - is part of what makes the mediator selection decision so important in insurance litigation.
Dealing with claims in Ontario, the process covered in this article is mediation under the Insurance Act, not arbitration.
Mediator Selection in Practice
There’s no guidance on who gets appointed to select the mediator. It can be anyone. In my experience, plaintiff counsel tend to choose another plaintiff lawyer practising in the area. Defence counsel are likely to pick a local external insurance defence lawyer. Going to someone outside of the firms or insurers involved is appropriate in both cases. These individuals can usually agree on a mediator within a single phone call.
The process is quick, easy, and in my experience, inexpensive. I haven’t seen anyone charge for appointing a mediator - it’s typically done out of collegial courtesy, or as a favour for a colleague.
When faced with the impasse, remind counsel that the procedure for picking a mediator is set out in s. 3 of Regulation 461/96 and ask whether a compromise can be reached. If not, name your person to appoint the mediator and ask counsel to do the same within 10 days.
Hamilton, ON Mediator FAQ
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Under s. 3(2) of Ontario Regulation 461/96, each party names one person within 10 days of the mediation request. Those two individuals then jointly appoint the mediator. It's a clean fallback mechanism - and one that plaintiff counsel rarely use, even when they should.
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Yes, without exception. Under s. 258.6(1) of the Insurance Act, both the plaintiff and the defendant's insurer are required to participate in mediation when either party requests it. The Court of Appeal confirmed in Keam v. Caddey, 2010 ONCA 565 that no legitimate basis exists to refuse.
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No. In Thomson v. Portelance, 2018 ONSC 1278, the Ontario Superior Court was direct on this point: once a party requests mediation, the other side has a positive obligation to appoint a mediator and schedule the session within the timeframes set out in O. Reg. 461/96. Completion of discoveries is not a precondition.
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The defendant's insurer covers all reasonable mediator fees and expenses, as set out in s. 3(6) of Ontario Regulation 461/96. This applies to private mediations under s. 258.6(1) of the Insurance Act. Fees for court-connected mediations under Rule 24.1 are governed separately by O. Reg. 451/98.
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Significant. Under s. 258.6(2) of the Insurance Act, a party's failure to comply with the mediation obligation must be considered by the court when awarding costs. In Keam v. Caddey, the Court of Appeal increased the costs award by $40,000 as a remedial penalty against an insurer that twice refused to mediate - describing the conduct as "playing hardball." Defence counsel who advise clients to stall or refuse should be aware that courts have shown little patience for it.
In Closing
Under O. Reg. 461/96, mediation has to start within 14 days of the mediator’s appointment (if the parties can’t agree on a date). The session itself typically runs half a day to a full day, depending on the complexity of the case and the number of parties involved. Some mediations settle at the table. Others settle in the days or weeks that follow, after both sides have had time to consider what came out of it. There’s no statutory time limit on the session’s length.
Mediator selection disputes don’t have to stall a file. The procedure in O. Reg. 461/96 exists for exactly this situation, and it works - provided plaintiff counsel know to use it and move without hesitation when the defence starts running out the clock. If you’re dealing with an insurer that won’t engage on mediation, or you need an experienced mediator for litigation in Ontario, contact Cook Reynolds to discuss your options.