PHI vs PII: What's the Difference (and Why It Matters in Healthcare)
In healthcare, "PHI" and "PII" are often used interchangeably in meetings, tickets, training decks, and vendor questionnaires. That shorthand is understandable—but it can cause expensive problems.
TL;DR
PII is information that identifies a person (across industries). PHI is identifiable health information in a HIPAA-covered context (healthcare-specific). ePHI is PHI in electronic form. In healthcare environments, PHI often includes PII—but not all PII is PHI, and not all health data is PHI.
Important: This article is for general information, not legal advice. Definitions and obligations can vary based on your role, contracts, state law, and the facts of an incident. Confirm decisions with your privacy/compliance and legal teams.
Table of Contents
Fast definitions: PHI, PII, and ePHI
What is PII?
PII (Personally Identifiable Information) generally means information that can identify a person—directly (like a full name) or indirectly (like a unique identifier that can be tied back to them).
PII is used broadly across industries (finance, retail, government). It is also commonly referenced in security programs even when the legal definition differs.
What is PHI?
PHI (Protected Health Information) is identifiable health information that is handled in a HIPAA-covered context—typically by a covered entity or a business associate.
PHI typically relates to a person's health condition, care, or payment for care—and includes identifiers.
What is ePHI?
ePHI is PHI in electronic form. The "e" matters because technical controls—access control, encryption, logging, DLP, endpoint management—apply most directly to electronic systems.
Quick classification shortcut:
If it identifies a person, it may be PII.
If it identifies a person and relates to healthcare or payment in a HIPAA context, it may be PHI.
If that PHI lives in systems/files/messages, it is likely ePHI.
Why the difference matters (for CISOs and compliance)
In healthcare security programs, "PHI vs PII" is not just semantics. It affects:
- Scope: what systems are in your HIPAA Security Rule scope and what systems still need strong privacy controls
- Vendor contracting: when you need a BAA vs a standard DPA, and what controls and audit rights you require
- Incident response: what notifications and timelines may apply, who owns the decision, and what evidence you must preserve
- Training: what staff should avoid sharing in tickets, chat, email, and AI tools
- Data strategy: how to use data for analytics and AI while reducing identification risk
The operational reality: staff don't label data correctly
Most frontline staff do not think in regulatory categories. They think in tasks. If your program relies on staff perfectly identifying PHI vs PII in the moment, you will lose. Instead, build:
- Safe defaults (approved channels, templates, redaction)
- Automation (warnings, DLP, access controls)
- Clear examples ("Don't paste patient names into tickets; use record IDs.")
PHI vs PII: quick comparison matrix
| Dimension | PII | PHI | ePHI |
|---|---|---|---|
| What it is | Data that identifies a person | Identifiable health/payment info in HIPAA context | PHI stored/transmitted electronically |
| Industry scope | Any industry | Healthcare-specific | Healthcare-specific |
| Does context matter? | Less; it's about identifiability | Yes; who holds it and why matters | Yes; also depends on system/transmission |
| Typical examples | Name, email, phone, SSN | Patient name + appointment; MRN + lab results | PHI in EHR, email, cloud docs, tickets |
| Main risks | Identity theft, fraud, privacy harm | Privacy harm + regulatory exposure | Same as PHI + broader cyber risk |
Is PHI considered PII?
Often, yes—PHI frequently contains identifiers, so it often overlaps with PII. But it helps to be precise:
- PHI is not "a type of PII" everywhere. PHI is a healthcare-specific concept tied to HIPAA context.
- Many PHI elements contain PII. Patient name, address, email, phone number, MRN, and dates can all be identifying.
- Not all PII is PHI. A hospital employee's payroll records may be PII but not PHI.
Useful way to say it internally: "PHI is often PII, plus healthcare context."
Common healthcare examples (and how to label them)
| Data element | Usually PII? | Usually PHI? | Notes |
|---|---|---|---|
| Patient name in provider system | Yes | Often yes | Treat as PHI in provider environment |
| Employee name in HR/payroll | Yes | No (typically) | Still sensitive, usually not HIPAA PHI |
| Medical record number (MRN) | Often | Often yes | Strong internal identifier |
| Diagnosis code + patient name | Yes | Yes | Classic PHI example |
| Appointment reminder with name | Yes | Often yes | Care provision context is enough |
| Insurance ID + claim status | Yes | Often yes | Payment for care tied to individual |
| De-identified dataset | Not necessarily | Not necessarily | Still sensitive due to re-identification risk |
| IP address from patient portal | Sometimes | Could be | Becomes identifying when tied to portal accounts |
Operational rule: If the artifact can identify a patient and relates to care or payment, treat it as PHI and handle it through approved channels.
Edge cases that confuse teams
1) A list of patient names (no diagnoses)
Many teams assume a list of names is "just PII." In a healthcare provider context, a patient list can still be treated as PHI because it can indicate the individual received healthcare services.
2) Marketing and outreach data
Healthcare outreach campaigns can include identifiers and care context. Even when the content feels "non-clinical," it may still be regulated internally as PHI.
3) Call recordings and voicemails
A voicemail that includes "My name is… my DOB is… I need my medication refilled" contains identifiers and care context. Treat recordings and transcripts as ePHI when they contain PHI.
4) Support tickets and chat threads
Many healthcare "incidents" are not sophisticated hacks—they are convenience leaks: an agent pastes a full portal message, a nurse posts a screenshot in the wrong channel.
5) Consumer health apps
Health data collected by consumer apps may be highly sensitive, but it is not automatically PHI under HIPAA unless handled by a HIPAA covered entity.
Where ePHI fits
In many organizations, the most important practical distinction is not PHI vs PII—it is PHI vs ePHI. That is because ePHI is where security programs can meaningfully apply technical controls at scale.
Examples of ePHI in everyday workflows
- EHR records and exports (PDFs, CCDAs, clinical summaries)
- email threads about patients and attachments
- cloud documents and shared drives containing patient data
- ticket attachments and screenshots
- chat transcripts in collaboration tools
- call transcripts stored in contact center platforms
Why this matters for CISOs
The "e" is what turns privacy rules into security engineering: identity and access management, encryption, logging and audit trails, DLP and content inspection, endpoint controls, data lifecycle controls.
De-identified data: when it's not PHI (and still risky)
Even if a dataset is not PHI under your chosen de-identification method, it can still create risk:
- Re-identification: linking to other datasets can reveal identities
- Inference: some models can infer sensitive attributes even from partial data
- Misuse: broad access invites unintended use cases
Minimum necessary: the rule that prevents oversharing
If you want one principle that reduces both PHI and PII exposure, it is this: share the minimum necessary to accomplish the task.
Minimum necessary in modern workflows
- In tickets: reference the record ID and describe the issue; avoid pasting notes and screenshots with identifiers
- In chat: do not post patient identifiers in broad channels; use approved secure messaging
- With vendors: share synthetic examples first; escalate to real data only when necessary
- With AI tools: prefer redacted text and structured summaries over raw patient communications
Training line that works: "Use IDs, not identities."
How to classify data in practice (a workable framework)
A simple 4-tier model for healthcare teams
| Tier | Examples | Handling |
|---|---|---|
| Tier 1: Regulated clinical sensitivity (PHI/ePHI) | Clinical notes, lab results, imaging, claims | Approved systems only; strict access control; logging; encryption |
| Tier 2: High-risk identifiers (PII) | SSN, driver's license, passport, payroll IDs | Restricted storage; encryption; strong IAM; monitoring |
| Tier 3: Operational sensitive | Internal HR issues, security incidents, vendor credentials | Role-restricted; avoid broad sharing; controlled tools |
| Tier 4: Public / non-sensitive | Published content, general education materials | Normal collaboration tools permitted |
Controls that reduce PHI/PII exposure across real workflows
The most effective programs don't just say "don't share PHI." They make it hard to do the wrong thing accidentally.
1) Control where PHI can go (approved channel strategy)
- Define approved messaging and file storage for PHI
- Block or discourage PHI in tools not designed for it
- Document exceptions and require justification
2) Content-aware guardrails (practical DLP)
- Detect identifiers in outbound email and chat
- Show "are you sure?" prompts when sharing externally
- Scan ticket attachments and warn when they contain identifiers
3) Reduce bulk exports
- Build report access inside controlled systems
- Use time-limited links instead of attachments
- Monitor unusual export patterns
4) Identity, access, and auditing
- Role-based access aligned to job functions
- MFA for privileged access and remote access
- Regular access reviews
5) Endpoint controls
- Full-disk encryption for laptops
- MDM for mobile devices accessing portals
- Screen lock policies and idle timeouts
6) Vendor controls that match your PHI reality
- BAA when PHI is handled
- Data retention limits and deletion SLAs
- Access logging, admin roles, and support access constraints
PHI/PII in AI workflows (LLMs, summarization, copilots)
AI is where PHI vs PII confusion becomes a real risk—fast. People paste text into tools to save time, and the tool's output looks helpful, so the behavior spreads.
Common AI use cases that accidentally include PHI
- summarizing patient portal messages
- drafting letters to patients or payers
- generating ticket summaries from screenshots
- creating "examples" for training using real incidents
- extracting structured fields from unstructured notes
A safer operating model for AI in healthcare
- approved tools only for workflows that may involve PHI
- clear data boundaries (what can be sent, what cannot)
- redaction/masking as a default step before prompting
- logging and oversight for prompts/outputs where required
Incident triage: questions to ask when data is exposed
When something goes wrong, the PHI vs PII distinction shapes triage and escalation.
First questions to ask
- What data was involved? Names, MRNs, DOBs, diagnoses, claims, credentials, screenshots?
- Can it identify a person? Directly or indirectly?
- Does it relate to care, payment, or healthcare operations?
- Who received it / could access it?
- How long was it exposed?
- Can we revoke access?
- Do we have logs?
Program takeaway: If your incident process begins with "Is this PHI?" you will lose time. Start with "Can someone be harmed?" and "Can we contain it?"
Frequently Asked Questions
Is PHI the same as PII?
Is a patient's name PHI or PII?
Is an appointment reminder PHI?
What is ePHI?
If data is 'de-identified,' is it still PHI?
What is the easiest way to avoid PHI/PII mistakes?
Protect PHI and PII in your AI workflows
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