Ontario acts: PHIPA

PHIPA & AI in Healthcare (Ontario): Overview

The Personal Health Information Protection Act, 2004 (PHIPA) is Ontario’s health-specific privacy law that governs how
health information custodians (HICs) and their agents/service providers collect, use, disclose, and safeguard
personal health information (PHI). While PHIPA predates modern AI, it applies directly when AI systems access,
process, analyze, or generate PHI in clinical or administrative workflows.

Primary legislation: PHIPA, 2004 (Ontario e-Laws) 
Core regulation: O. Reg. 329/04 (General)
Oversight & guidance: Information and Privacy Commissioner of Ontario (IPC) – Health

History & Scope

Enacted in 2004, PHIPA establishes a comprehensive framework for PHI privacy, confidentiality, accuracy, and security across Ontario’s
health sector. It provides individuals with rights to access and correct their PHI and requires custodians to implement
administrative, technical, and physical safeguards against unauthorized access, use, or disclosure.

  • Who is a Health Information Custodian (HIC)?
  • Hospitals, physicians, nurses, pharmacies, laboratories, long-term care homes, medical clinics, medical officers of health, and other prescribed organizations.

  • Who are Agents/Service Providers?
  • Individuals or organizations acting for or on behalf of a HIC (e.g., IT service providers, AI vendors), subject to PHIPA through contractual and policy controls.

  • What is PHI?
  • Identifying information about an individual in oral or recorded form that relates to health, healthcare, provision of care, payments, eligibility, donor information, or a health number.

Helpful overviews:
IPC: PHIPA Overview 
IPC Guidance Library

Relevance to AI in Healthcare

PHIPA applies when AI systems touch PHI—whether for clinical decision support, triage, diagnostic assistance, virtual care,
telemonitoring, predictive modeling,
or administrative analytics. Even if an AI tool is operated by a vendor, the HIC remains

accountable for PHI under PHIPA and must ensure the vendor acts as an agent with proper safeguards and policies.

  • – AI-enabled decision support embedded in EMRs/EHRs
  • – Telehealth platforms, virtual triage, symptom checkers
  • – Remote patient monitoring and device telemetry analytics
  • – Natural language tools processing clinical notes or referrals
  • – Population health analytics using de-identified or pseudonymized PHI

Key PHIPA Obligations (AI Context)

  • Consent & Purpose Limitation — Collection, use, and disclosure of PHI must align with the individual’s consent and the specified purposes.
    Secondary uses (e.g., training a new model) generally require additional consent or robust de-identification.
    See: IPC: Consent & Capacity

  • Circle of Care & Lock-Box Concepts — PHI may be shared among providers for direct care within the circle of care; individuals can restrict sharing (“lock-box”) in many cases.
    See: IPC: Circle of Care (guide)

  • Safeguards — Reasonable administrative, technical, and physical safeguards proportionate to sensitivity (e.g., RBAC/ABAC, encryption, strong authentication, audit logging, network segmentation, secure MLOps).
    Reg. reference: O. Reg. 329/04, s. 12 (Security)

  • Access & Correction Rights — Individuals can request access to and correction of their PHI; processes must be documented and timely.
    Statute: PHIPA, Part V (Access & Correction)

  • Agent Accountability — Vendors handling PHI on behalf of HICs are agents; HICs must have contracts, training, and oversight to ensure PHIPA compliance.
    Statute: PHIPA, s. 17 (Agents)

  • Electronic Health Records (EHR) — Additional duties for prescribed organizations and EHR contexts (e.g., logging, access management).
    Reg. reference: O. Reg. 329/04

AI-Specific  Considerations Under PHIPA

  • Training vs. Care Delivery — Distinguish PHI used for direct care (implied consent often applies) from PHI used for model training, tuning, or QA (often requires express consent or de-identification).

  • De-identification & Re-identification Risk — Apply rigorous de-identification and document residual risk; recognize that linkage attacks and powerful models can increase re-identification likelihood.
    See: IPC De-identification Guidelines

  • Explainability & Transparency — Provide understandable rationales for AI-supported decisions affecting care; support audits and patient inquiries with traceability.

  • Bias & Fairness — Evaluate datasets and models for differential performance; document mitigations and implement ongoing monitoring to protect patient rights.

  • Cross-Border Processing — PHIPA does not outright prohibit storage/processing outside Ontario/Canada, but HICs remain accountable for comparable protections, transparency, and contractual safeguards with service providers.
    See: IPC: Health Info & Electronic Service Providers

  • Security for AI Pipelines — Protect training data, feature stores, model artifacts, prompts/outputs (LLMs), and inference endpoints; implement tamper-evident logging and secure key management.

Emerging Challenges

  • Data Minimization vs. Data-Hungry Models — AI often seeks large datasets; PHIPA requires limiting collection/retention to what is necessary for identified purposes.

  • Secondary Use & Purpose Creep — Re-purposing PHI for new AI projects typically requires new consent or robust de-identification with documented risk analysis.

  • Vendor Ecosystems — Multi-party models (clouds, APIs, model hosts) increase complexity; HICs must maintain oversight and ensure each party’s obligations are clear and enforceable.

  • Auditability — Ensuring complete audit trails across data pipelines and ML lifecycle (training, deployment, monitoring, rollback) is essential for PHIPA accountability.

Strategies for PHIPA-Aligned AI Deployments

  • Privacy Impact Assessments (PIAs) — Perform early and update for material changes (new data sources, features, model versions, vendors).
    See: IPC: PIA FAQs

  • Data Classification & Minimization — Map PHI elements; segregate identifiers; minimize retention; automate deletion workflows.

  • Contracts & Oversight for Agents — Define security obligations, subcontracting limits, breach notification, audit rights, and logging/monitoring requirements for AI vendors.

  • Explainability Layers & Model Cards — Provide clinical rationales, confidence intervals, known limitations, and monitoring plans; maintain documentation for audits.

  • Security by Design — RBAC/ABAC, MFA, encryption at rest/in transit, secrets management, network segmentation, SAST/DAST for AI services, supply-chain controls for models and data.

  • Breach & Incident Response — Expand playbooks to include model rollback, dataset quarantine, access revocation, and timely notification as required by PHIPA and regulations.

  • Training & Awareness — Educate clinicians, engineers, and data scientists on PHIPA duties, consent patterns, and safe AI usage.

Interplay With Other Laws & Standards

PHIPA coexists with federal and provincial privacy regimes and can be strengthened by aligning with recognized security/AI frameworks:

  • PIPEDA (federal) — Applies to commercial activities and interprovincial/cross-border flows for private-sector organizations.
    Link: PIPEDA

  • Bill C-27 (proposed) — Would enact the CPPA and AIDA for modernized private-sector privacy and risk-based AI governance.
    Links: LEGISinfo
    ISED: AIDA

Operational Checklist (AI Under PHIPA)

  • – Define clear purposes for each AI use; verify consent basis (implied vs. express) and lock-box preferences.
  • – Perform and update PIAs for new models, datasets, and vendors.
  • – Implement RBAC/ABAC, encryption, secrets management, and tamper-evident audit logging across the ML pipeline.
  • – Adopt model cards, bias testing, drift detection, human-in-the-loop controls, and rollback procedures.
  • – Contractually bind agents/service providers to PHIPA-aligned obligations; assess cross-border risks and controls.
  • – Publish plain-language notices describing AI’s role; enable access/correction processes for PHI.
  • – Run incident tabletop exercises covering AI failure modes and PHI breach scenarios; define notification triggers.

References & Official Sources