HIPAA governs how Protected Health Information (PHI) is handled in the United States healthcare ecosystem. The engineering surface area is large because PHI is broader than people often realize: a calendar entry naming a patient's appointment is PHI; an IP address logged on a portal accessed by a patient may be PHI in combination with a health condition.
The skill is structured around the four HIPAA rules with emphasis on the Security Rule's three safeguard categories (Administrative / Physical / Technical) — that's where engineering work happens. Privacy Rule, Breach Notification Rule, and HITECH layer on top.
Final compliance determinations stay with counsel and your privacy officer; this skill is the technical engineering layer.
Cross-references: privacy-engineering for the GDPR / CCPA-shaped privacy work that often overlaps; iam-audit for access control and authentication; crypto-audit for encryption-at-rest and in-transit detail; secrets-audit for key management; siem-detection for audit-log engineering; incident-triage and security-comms for breach response.
Scope — who is covered and what is PHI
Who must comply
- Covered entity (CE) — health plans, healthcare clearinghouses, healthcare providers who transmit health info electronically in connection with HIPAA-defined transactions
- Business associate (BA) — anyone who creates / receives / maintains / transmits PHI on behalf of a covered entity (cloud hosts holding PHI, SaaS analytics, EHR vendors, billing services, even some attorneys and consultants)
- Subcontractor of a BA — also a BA. The chain extends; every link needs a BAA with the link above
If a system handles PHI for a CE without a BAA, that's a violation regardless of how secure the handling is.
What is PHI / ePHI
PHI = individually identifiable health information held or transmitted by a CE or BA. ePHI = the electronic form.
The 18 HIPAA identifiers (Safe Harbor de-identification list — if all are stripped, data is no longer PHI):
- Names
- Geographic subdivisions smaller than state (street, city, county, ZIP — full ZIP if population < 20,000; first 3 digits OK in most cases)
- Dates more specific than year (DOB, admission, discharge, death) — for individuals over 89, even the year requires aggregation
- Phone numbers
- Fax numbers
- Email addresses
- Social Security numbers
- Medical record numbers
- Health plan beneficiary numbers
- Account numbers
- Certificate / license numbers
- Vehicle identifiers and serial numbers (including license plates)
- Device identifiers and serial numbers
- URLs
- IP addresses
- Biometric identifiers (finger, voice)
- Full-face photographs and comparable images
- Any other unique identifying number, characteristic, or code
Important: removing the 18 identifiers via Safe Harbor is one of two de-identification methods. The other is Expert Determination (statistical analysis confirming low re-identification risk). De-identified data is not PHI; pseudonymized data is still PHI (because the key linking the surrogate back to the individual is still held somewhere).
Scope reduction patterns
The most common scope reductions:
- Limit data classes collected — if you don't need DOB, don't collect it; don't transmit it; don't store it
- Pseudonymize internally where regulators allow, but understand that internal pseudonyms are still ePHI (the linking table is held by the CE / BA)
- Use BA-signed services where possible — AWS, Google Cloud, Azure, Stripe Healthcare, certain analytics vendors sign BAAs; many SaaS tools do not
- Use services that contractually commit to never receive PHI — analytics platforms that scrub on ingest, error reporters with strict PII filtering
Security Rule — the three safeguard categories
Administrative safeguards (program-level)
These are policy and program controls. Engineering teams contribute artifacts; the privacy officer owns the program.
- §164.308(a)(1) Security Management Process — risk analysis (the foundation; redone on material change), risk management, sanction policy, information system activity review
- §164.308(a)(2) Assigned Security Responsibility — a named Security Official
- §164.308(a)(3) Workforce Security — authorization / supervision, termination procedures
- §164.308(a)(4) Information Access Management — access authorization, modification
- §164.308(a)(5) Security Awareness and Training — including security reminders, malicious software protection, log-in monitoring, password management
- §164.308(a)(6) Security Incident Procedures — see
incident-triage - §164.308(a)(7) Contingency Plan — backup, disaster recovery, emergency mode operation, testing
- §164.308(a)(8) Evaluation — periodic technical and non-technical evaluation
- §164.308(b)(1) Business Associate Contracts — BAA with every BA
Engineering audit input: evidence packages for risk analysis (asset inventory, threat model, controls list), workforce-security records (access reviews, joiner/mover/leaver evidence), training completion records.
Physical safeguards (data center / facility)
For modern SaaS, most physical safeguards are inherited from the cloud provider's compliance posture (covered by the cloud's BAA). Verify:
- §164.310(a) Facility Access Controls — for any office space where ePHI is processed
- §164.310(b) Workstation Use — policies for workstations that access ePHI
- §164.310(c) Workstation Security — physical security of those workstations
- §164.310(d) Device and Media Controls — disposal, media re-use, accountability, data backup and storage
Engineering audit input: confirm cloud provider's BAA covers the relevant physical-safeguard obligations; confirm workstation disk encryption and remote-wipe for any employee laptop touching ePHI.
Technical safeguards (where engineering audits)
This is where this skill spends its time.
§164.312(a) Access Control
- Unique user identification — required. Every individual accessing ePHI has a unique ID. No shared accounts
- Emergency access procedure — break-glass path for emergency PHI access, logged
- Automatic logoff — addressable; idle session termination
- Encryption and decryption — addressable; encrypt ePHI at rest (in practice, treat as required; OCR enforcement strongly suggests this)
Audit grep patterns:
- Shared service-account access to PHI tables:
SELECT.*patient,SELECT.*encounterfrom non-individual accounts - Lack of session timeout: search for session config without explicit timeout
- Unencrypted ePHI at rest: confirm DB-level + bucket-level encryption per data store
§164.312(b) Audit Controls
- Hardware, software, and procedural mechanisms that record and examine activity in systems containing ePHI
In practice: every read, every write, every access decision involving ePHI logged. Logs preserved for at least 6 years (HIPAA's general document-retention period). See siem-detection for the engineering implementation.
§164.312(c) Integrity
- Mechanisms to authenticate ePHI — verify ePHI has not been altered or destroyed in unauthorized manner
- Addressable in practice — hash / signature controls on critical ePHI records, immutable log storage
§164.312(d) Person or Entity Authentication
- Verify identity of person or entity accessing ePHI
- MFA is not explicitly required by Security Rule text — but post-2013 enforcement and HHS guidance strongly recommend MFA for any remote access to ePHI; treat as effectively required. New HHS guidance (2024+) is moving MFA toward explicit requirement
See iam-audit for implementation.
§164.312(e) Transmission Security
- Integrity controls — addressable; protect ePHI in transit from improper modification
- Encryption — addressable in text but treat as required; TLS 1.2+ for any ePHI traversing networks
See crypto-audit.
Privacy Rule — what can be done with PHI
The Privacy Rule sets the rules for how PHI is used and disclosed. The Security Rule says "protect it"; the Privacy Rule says "you can only use it for these specific purposes."
Engineering-relevant slices:
- Minimum Necessary Standard — when using or disclosing PHI for purposes other than treatment, use or disclose only the minimum necessary. The engineering implementation: role-based access, query-level scoping (don't
SELECT *from patient tables), API contracts that return only the fields the caller needs - TPO exception — Treatment, Payment, and Healthcare Operations do not require authorization. Most other uses do
- Individual rights — right to access (similar to GDPR DSAR — 30-day delivery), right to amend, accounting of disclosures
- Notice of Privacy Practices — published, presented at first interaction
Audit grep patterns:
- Over-broad PHI queries:
SELECT \*.*patient,SELECT \*.*encounter,SELECT \*.*observation— almost always a minimum-necessary violation - API endpoints returning full patient records when callers only need specific fields
- Analytics platforms / monitoring tools receiving PHI without a TPO basis
Breach Notification Rule
A breach is the unauthorized acquisition, access, use, or disclosure of unsecured PHI that compromises the security or privacy of the PHI. "Unsecured" = not encrypted per HHS guidance (encryption is the safe harbor).
Notification timing:
| Recipient | Timing |
|---|---|
| Affected individuals | Without unreasonable delay, no later than 60 calendar days after discovery |
| Department of Health and Human Services (HHS / OCR) | Within 60 days of discovery for breaches affecting ≥ 500 individuals; annually for breaches < 500 |
| Media | Same 60-day window for breaches affecting > 500 in a state or jurisdiction |
| Business associate to covered entity | Without unreasonable delay, no later than 60 days |
A "breach" includes the unauthorized access — not just exfiltration. If a workforce member views a record they had no need to view, that is a breach (unless one of the limited exceptions applies).
Engineering hook: ability to scope a breach quickly. Audit logs (Security Rule §164.312(b)) are the source of truth. Time-to-scope directly impacts the 60-day clock.
Safe harbor: if the PHI was encrypted per HHS-recognized standards (and the key wasn't also compromised), the unauthorized acquisition may not be a breach. This is the strongest reason to encrypt ePHI at rest comprehensively.
See incident-triage (response), security-comms (notification draft — legal review required), breach-patterns (post-incident pattern extraction).
HITECH layer
HITECH (2009) strengthened HIPAA in several ways relevant here:
- Made BAs directly liable for many Security Rule violations (was previously CE-only)
- Increased civil monetary penalties (tiered up to $1.5M per provision per year)
- Made the Breach Notification Rule federal (replacing some state-level patchwork)
- Strengthened the right of patients to obtain electronic copies of their PHI
For modern engineering work, HITECH means: a BA that handles ePHI is subject to most of the Security Rule directly. Vendors cannot hide behind the CE.
Audit checklist
# HIPAA Audit Findings
## Entity: [name]
## Entity type: Covered Entity / Business Associate / Subcontractor
## Date: [date]
## Auditor: [name]
### Scope
- [ ] ePHI inventory complete (every data store containing PHI)
- [ ] Data flow diagrams for PHI transmission paths
- [ ] BAA in place with every BA (and BA's subcontractors where required)
- [ ] Cloud provider BAA on file (AWS / GCP / Azure / etc.)
- [ ] Risk analysis (§164.308(a)(1)(ii)(A)) current
### Administrative safeguards
| Subsection | Status | Findings |
|------------|--------|----------|
| Security Management Process | | |
| Assigned Security Responsibility | | |
| Workforce Security | | |
| Information Access Management | | |
| Security Awareness and Training | | |
| Security Incident Procedures | | |
| Contingency Plan | | |
| Evaluation | | |
| BA Contracts | | |
### Technical safeguards
| Subsection | Status | Findings |
|------------|--------|----------|
| Access Control — unique IDs | | |
| Access Control — emergency access | | |
| Access Control — automatic logoff | | |
| Access Control — encryption at rest | | |
| Audit Controls | | |
| Integrity | | |
| Person / Entity Authentication (MFA) | | |
| Transmission Security (encryption in transit) | | |
### Privacy Rule
- [ ] Minimum necessary applied in code (no SELECT * on PHI tables)
- [ ] Notice of Privacy Practices published and presented
- [ ] Individual access path implemented (30-day delivery)
- [ ] Amendment / accounting of disclosures process exists
### Breach response readiness
- [ ] Audit logs sufficient to scope a breach within 60-day clock
- [ ] Incident-response procedures tested
- [ ] Notification templates drafted (see security-comms)
- [ ] Encryption-as-safe-harbor verified across ePHI stores
### Findings detail
[Per finding: section reference, severity, location, evidence, remediation]
### Recommendations
[Prioritized]
Disposition rule (Fixed / Deferred / Accepted Risk) per owasp-audit. HIPAA accepted-risk is highly disfavored — most "accepted risks" should be documented as residual risk with compensating controls and re-evaluation triggers.
Common audit findings (real-world starting hypotheses)
- PHI in non-BAA vendor pipelines — Sentry, Datadog, Mixpanel, Segment, Slack receiving PHI without a BAA (Sentry has a BAA path; Datadog has a healthcare offering; Mixpanel does not by default — verify each vendor's BAA stance)
- Unique-user-ID violation via shared service accounts — engineering team uses a shared admin account for ad-hoc PHI access
SELECT *on PHI tables — minimum-necessary violation; API serializers returning all fields when callers need few- DOB stored when only age range needed — minimization gap
- Backups encrypted but with key co-located — safe harbor depends on key separation
- Lower environments seeded from production — staging DB contains real PHI from a prod dump
- MFA not enforced for all ePHI access paths — pre-2024 environments may have gaps; trend is toward universal MFA requirement
- Audit log retention < 6 years — HIPAA's 6-year retention applies to documentation required by the rules, including audit logs that evidence compliance
- No automatic logoff on ePHI-accessing workstations / clinical applications
- BA chain breaks — vendor's subcontractor handles ePHI but the BA never put their own BAA in place with the subcontractor
Boundaries
- This skill is the engineering audit and preparation. Privacy Officer / counsel make final determinations on covered-entity status, BA relationships, and notification decisions
- Refuse to help build flows that violate HIPAA — PHI to non-BAA vendors, shared-account access to PHI, transmission of PHI via end-user messaging tech (consumer email, SMS, chat) outside narrow authorization, marketing uses of PHI without authorization
- For breaches: this skill scopes the breach and produces engineering inputs to the notification; the notification itself goes through
security-commsand counsel - HIPAA enforcement (OCR) has expanded since 2013; regulatory interpretation continues to evolve. Where this skill's content lags current OCR guidance, current OCR guidance prevails
- State laws may impose stricter requirements (e.g., Texas HB 300, California CMIA) — preempted only where state law is less protective; otherwise state requirements apply on top
- Genetic information has additional protections under GINA — out of scope here, refer to specialized guidance
References
- HHS HIPAA Rules —
hhs.gov/hipaa(regulatory text, FAQs, OCR resolution agreements) - HHS / OCR Audit Protocol — used by OCR auditors; useful checklist for self-assessment
- HHS Security Risk Assessment Tool — free tool for small/medium providers
- NIST SP 800-66 Rev. 2 (2024) — "Implementing the HIPAA Security Rule: A Cybersecurity Resource Guide" — the most current technical guidance
- HITRUST CSF — common controls framework that maps to HIPAA Security Rule; many BAs pursue HITRUST certification as compliance evidence
- OCR Resolution Agreements — published enforcement actions; useful precedent for what OCR considers material
- HHS Wall of Shame — public breach portal; useful for industry-pattern context
- 45 CFR Parts 160 and 164 — the regulatory text itself
- OCR Cybersecurity Newsletter — quarterly guidance updates
- "HIPAA Plain & Simple" — Carolyn P. Hartley — practitioner reference