What Is Vicarious Liability in Medical Malpractice — And Who Are You Actually Suing?

One of the aspects of medical malpractice law that surprises many potential claimants is the question of who, precisely, is the appropriate defendant in a claim. The instinctive answer (the doctor, or the nurse, or the practitioner whose conduct is in question) is not always the legally correct one. In many medical malpractice cases in Canada, the appropriate defendant is not the individual practitioner but the institution or employer on whose behalf that practitioner was acting. Understanding why requires an understanding of the legal concept of vicarious liability.

Vicarious liability is a foundational principle of Canadian tort law. It operates in many contexts beyond healthcare, but its application in the medical malpractice setting has specific and important implications for how claims are structured, who carries the financial responsibility for compensation, and how the interests of all parties, including patients, practitioners, and institutions, interact within the litigation process.

What Vicarious Liability Means

In its simplest terms, vicarious liability is the legal principle by which one party is held liable for the wrongful acts of another, not because of any direct wrongdoing on their own part, but because of the relationship that exists between them. In an employment context, this means that an employer can be held legally responsible for the negligent acts of an employee committed in the course of their employment.

Applied to healthcare, vicarious liability typically means that where a nurse, a resident physician, a technician, or another employed healthcare worker commits an act of negligence in the course of their duties, the legal claim arising from that negligence is brought not against the individual employee but against their employer: most commonly a hospital, a regional health authority, or another healthcare institution.

The practical effect of this is significant. In most cases involving employed healthcare workers in Canadian hospitals and healthcare institutions, the defendant named in a medical malpractice claim will be the institution rather than the individual practitioner. The institution carries the insurance, absorbs the financial liability, and is represented by defence counsel, while the individual practitioner whose conduct is at issue may be a witness rather than a named party.

how the structure of a medical malpractice claim affects what must be proven

Why Vicarious Liability Exists — The Policy Rationale

The principle of vicarious liability is not arbitrary. It reflects deliberate policy choices about where financial responsibility for negligence should lie, and about the incentive structures that produce safer systems.

First, institutions are generally better positioned than individual employees to bear the financial consequences of negligence. A hospital or regional health authority carries insurance for this purpose, and has the organizational resources to respond to a damages award or settlement. An individual nurse or resident physician typically does not have the same financial capacity, and holding them personally liable for the full consequences of negligence committed in the course of their employment would be both individually devastating and practically inefficient.

Second, and perhaps more importantly, vicarious liability creates a powerful institutional incentive for employers to invest in training, supervision, systems, and safety culture. If a hospital knows it will bear the financial consequences of negligent acts committed by its employees, it has a strong interest in ensuring that its employees are adequately trained, appropriately supervised, and working within systems that minimize the risk of error. That incentive operates at the systemic level in a way that individual liability alone cannot replicate.

Third, vicarious liability reflects the reality that in many cases of healthcare negligence, the error is not purely the product of an individual's failings; it is the product of a system, a culture, a set of pressures, or a failure of supervision or training that the institution itself is responsible for addressing. Holding the institution liable acknowledges that accountability for healthcare safety operates at multiple levels.

When Vicarious Liability Applies — And When It Does Not

Vicarious liability applies where the negligent act was committed by an employee acting within the scope of their employment. In a hospital or healthcare institution setting, this covers the vast majority of clinical care provided by nurses, allied health professionals, residents, and other employed staff.

The situation is more complex for physicians. In Canada, many physicians, particularly in hospital settings, are not employees of the hospitals where they practice. They are independent practitioners who hold hospital privileges, meaning they are granted the right to admit and treat patients within the institution but are not in an employment relationship with it. In those circumstances, the hospital may not be vicariously liable for the physician's negligence, and the claim may need to be brought against the physician directly, or against the physician's professional corporation, where one exists.

Independent physicians in Canada are required to maintain professional liability protection through the Canadian Medical Protective Association (CMPA), which is the primary provider of medical liability protection for physicians in this country. The CMPA is not an insurance company in the conventional sense; it is a not-for-profit mutual defence organization that provides legal defence and, where appropriate, indemnification to its physician members. The involvement of the CMPA in defending a physician defendant is a significant feature of the medical malpractice landscape in Canada, and one that experienced medical malpractice counsel will be thoroughly familiar with.

how the involvement of the CMPA affects the litigation of a medical malpractice claim

Nurse Practitioners and Independent Practice Settings

The employment status question also arises in the context of nurse practitioners and other advanced practice providers who may work in independent or semi-independent clinical settings, such as nurse practitioner-led clinics, or as independent contractors within a family medicine practice. In those settings, the practitioner may carry their own professional liability insurance rather than being covered under an institutional policy, and the structure of a potential claim will reflect that different relationship.

In Atlantic Canada, as in other Canadian jurisdictions, nurses who hold a nursing licence are generally required to carry professional liability protection, either through their employer's institutional coverage where they are employees, or through their own individual coverage where they are practising independently. The specific requirements vary by province and by practice setting, and identifying the correct defendant and the applicable insurance coverage is one of the early and important tasks in structuring a medical malpractice claim.

Multiple Defendants and Shared Liability

Medical care is rarely delivered by a single practitioner. A patient admitted to hospital may be cared for by a team that includes attending physicians, resident physicians, nurses, allied health professionals, technicians, and consultants from multiple specialties, each of whom may have owed a duty of care and each of whom may have contributed, to varying degrees, to the outcome that occurred.

In cases involving multiple potential defendants, a medical malpractice claim may name several parties (both individual practitioners and institutions), and the relative liability of each will be a matter for determination through the litigation process. Canadian tort law recognizes the possibility of apportioning liability among multiple defendants where each has contributed to the harm, and the rules governing contribution and indemnification between defendants are relevant to how such cases ultimately resolve.

Identifying all potentially liable parties at the outset of a claim, and structuring the claim to capture the full range of responsibility, requires both clinical expertise to understand what each practitioner's role was and what the standards applicable to each were, and legal expertise to translate that clinical picture into a properly structured legal proceeding.

why the involvement of multiple practitioners makes causation more complex

A Recent and Relevant Development in Atlantic Canada

The question of whether individual nurses could be named as personal defendants in medical malpractice claims, rather than having the hospital vicariously liable in their place, has been a topic of discussion and some concern within the nursing profession in Atlantic Canada and more broadly across the country. In New Brunswick, this issue attracted attention when there was a risk that individual nurses might be named personally in claims rather than the institutions employing them.

The response from the New Brunswick government at the time reflected a clear policy position in favour of maintaining institutional vicarious liability as the primary mechanism for addressing nursing negligence in the employment context, underscoring the broader principle that individual employed healthcare workers should generally not bear personal financial exposure for negligent acts committed in the course of their institutional employment.

This episode illustrates the extent to which the legal framework governing who bears liability in healthcare negligence cases is not static; it is subject to development, policy debate, and legislative intervention. Staying current with those developments is part of the expertise that experienced medical malpractice counsel brings to this work.

What This Means for Claimants

For a potential claimant, the practical implications of vicarious liability are straightforward in most cases: the claim will be brought against the institution whose employees were responsible for the care in question, and the institution's insurers and legal team will respond. The individual practitioners whose conduct is at issue will typically be witnesses rather than defendants, and the personal financial exposure of those practitioners is generally not directly at stake in the litigation.

This does not mean that individual practitioners are not accountable for their conduct. The regulatory college system, through which physicians, nurses, and other healthcare professionals are licensed and regulated in each Atlantic province, operates in parallel with the civil litigation system and provides a separate mechanism for professional accountability. A finding of negligence in civil litigation may have implications for a practitioner's standing with their regulatory college, even where they were not personally named as a defendant.

the relationship between a civil malpractice claim and a college complaint

For the purposes of a civil claim, what matters most to the claimant is that the party who bears financial responsibility for the harm suffered is properly identified and named from the outset, and that the claim is structured in a way that captures the full scope of the liability that exists. That requires a thorough understanding of the employment relationships, institutional structures, and insurance arrangements that govern the provision of healthcare in Atlantic Canada, understanding that Acuity Medical Law brings to every case it assesses.

how Acuity Medical Law structures and pursues claims on behalf of its clients