Reference catalog of test patterns by HIPAA Security Rule section (45 CFR §164). Pair with audit-trail-test-author for §164.312(b) audit-log requirements. Anchors: hhs.gov/hipaa (opens in new window) and NIST SP 800-66.
When to use
What is PHI?
Per HHS, PHI = individually identifiable health information + created/received/maintained/transmitted by a covered entity. The 18 HIPAA identifiers per §164.514(b)(2) (Safe Harbor):
1. Name
2. Geographic subdivisions smaller than state (ZIP codes need restrictions)
3. All elements of dates (except year) for dates directly related to an individual
4. Telephone numbers
5. Vehicle identifiers + license plates
6. Fax numbers
7. Device identifiers + serial numbers
8. Email addresses
9. Web URLs
10. SSN
11. IP addresses
12. Medical record numbers
13. Biometric identifiers (fingerprints, voiceprints)
14. Health plan beneficiary numbers
15. Full-face photos + comparable images
16. Account numbers
17. Any other unique identifying number / characteristic / code
18. Certificate / license numbersTest fixtures for HIPAA-scope systems MUST avoid these 18 identifiers (or use synthetic-pii-generator in the qa-test-data plugin to generate safe substitutes).
How to use
Test patterns by Security Rule section
Full per-section patterns live in references/security-rule-test-patterns.md, covering administrative safeguards (§164.308 workforce access management, workforce training), physical safeguards (§164.310 device + media disposal), technical safeguards (§164.312 access control, audit controls, integrity, transmission security), the §164.502(b) minimum-necessary standard, and §164.504(e) BAA-scope boundaries. Each entry is a copy-ready pytest-style test keyed to its CFR section.
Worked example
A billing clerk's role is added to the scheduling service. The team runs the §164.502(b) minimum-necessary pattern against /patient/123/billing-summary with the billing-clerk token. The response asserts amount_due and insurance_provider are present and that clinical_notes, medications, and genetic_test_results are absent. The negative assertion fails: the summary serializer eager-loads the full patient record, leaking medications. The team narrows the serializer to billing fields, re-runs, and the test passes, proving the role sees only the minimum-necessary PHI, with the read logged via the §164.312(b) audit pattern.
Anti-patterns
| Anti-pattern | Why it fails | Fix |
|---|---|---|
| Real PHI in test fixtures | HIPAA violation in tests | synthetic-pii-generator + de-identified data |
| Audit log without tamper-evidence | Logs can be modified post-incident | Hash-chain or signed-batch log integrity (§164.312(b)) |
| Role-based access without minimum-necessary check | Over-broad access; minimum-necessary violation | Per-PHI-type test (Step §164.502(b)) |
| Skip BAA scope tests | Vendor accesses PHI outside agreement | Step §164.504(e) scope test |
| Allow plaintext HTTP for PHI even in dev | Production drift; eventual leak | Always enforce HTTPS (Step §164.312(e)) |
Limitations
References
Test patterns by HIPAA Security Rule section (45 CFR §164). Pair §164.312(b) audit-log patterns with audit-trail-test-author. Fixtures must avoid the 18 Safe Harbor identifiers; use synthetic-pii-generator.
§164.308(a)(3) - Workforce access management
def test_user_role_grants_only_minimum_necessary_phi():
"""§164.502(b) minimum necessary standard."""
user = User.objects.create(role='billing-clerk')
# Billing clerks access financial PHI but NOT clinical notes
assert user.can_access(PhiType.BILLING)
assert not user.can_access(PhiType.CLINICAL_NOTES)
assert not user.can_access(PhiType.GENETIC_TEST_RESULTS)§164.308(a)(5) - Workforce training
Test that training-completion is enforced before access grant:
def test_user_cannot_access_phi_without_training_completion():
user = User.objects.create(role='nurse', hipaa_training_completed=False)
response = client.get('/patient/123/records', headers={'Authorization': f'Bearer {user.token}'})
assert response.status_code == 403
assert 'training_required' in response.json()['error']§164.310(d)(2) - Device + media disposal
def test_phi_overwritten_when_device_decommissioned():
device = Device.objects.create(serial='ABC123', has_phi=True)
decommission(device)
# Device record marked as wiped + audit log entry
device.refresh_from_db()
assert device.status == 'wiped'
assert device.wipe_method in ['NIST 800-88 Clear', 'NIST 800-88 Purge']
assert AuditLog.objects.filter(action='device_wipe', subject=device.serial).exists()§164.312(a)(1) - Access control
def test_phi_access_requires_unique_user_id():
"""§164.312(a)(2)(i) Unique User Identification - no shared accounts."""
# System must reject login attempts on generic / shared accounts:
response = client.post('/login', json={'username': 'admin', 'password': 'secret'})
assert response.status_code == 403 # generic 'admin' account forbidden§164.312(b) - Audit controls
Cross-ref audit-trail-test-author:
def test_phi_access_creates_audit_record():
"""§164.312(b): record + examine activity in info systems containing PHI."""
user = User.objects.create(role='nurse')
client.get(f'/patient/{patient.id}/records', headers={'Authorization': f'Bearer {user.token}'})
audit = AuditLog.objects.filter(
actor=user.id,
action='phi_access',
subject=f'patient:{patient.id}',
).first()
assert audit is not None
assert audit.timestamp is not None
assert audit.tamper_evident_hash is not None # required for integrity§164.312(c)(1) - Integrity
def test_phi_modification_requires_authentication_and_audit():
"""§164.312(c)(1): protect ePHI from improper alteration / destruction."""
user_unauth = User.objects.create(role='intake-staff')
response = client.put(
f'/patient/{patient.id}/records',
json={'diagnosis': 'modified'},
headers={'Authorization': f'Bearer {user_unauth.token}'},
)
assert response.status_code == 403 # intake staff cannot modify clinical
# Even authorized modification is logged:
user_doc = User.objects.create(role='physician')
response = client.put(
f'/patient/{patient.id}/records',
json={'diagnosis': 'updated'},
headers={'Authorization': f'Bearer {user_doc.token}'},
)
audit = AuditLog.objects.filter(
action='phi_modify',
subject=f'patient:{patient.id}',
actor=user_doc.id,
).first()
assert audit.before_value == 'original'
assert audit.after_value == 'updated'§164.312(e)(1) - Transmission security
def test_phi_transmitted_only_via_encrypted_channels():
"""§164.312(e)(2)(ii): encryption in transit for PHI."""
# Plaintext HTTP must redirect or refuse:
response = http_client.get('http://api.example.com/patient/123')
assert response.status_code in [301, 308, 403]
# HTTPS must use TLS 1.2+ + secure ciphers:
tls_info = inspect_tls('https://api.example.com')
assert tls_info.protocol >= 'TLSv1.2'
assert tls_info.cipher in ALLOWED_CIPHERS§164.502(b) - Minimum necessary standard
def test_query_returns_only_minimum_necessary_fields():
response = client.get(
'/patient/123/billing-summary',
headers={'Authorization': f'Bearer {billing_clerk_token}'},
)
body = response.json()
# Billing summary should NOT include clinical notes or sensitive fields:
assert 'amount_due' in body
assert 'insurance_provider' in body
assert 'clinical_notes' not in body
assert 'medications' not in body
assert 'genetic_test_results' not in body§164.504(e) - Business Associate Agreement scope
def test_phi_only_processed_for_baa_purposes():
# Test fixture: BAA scope = appointment-scheduling only
baa = BusinessAssociateAgreement.objects.get(partner='SchedulingVendor')
assert baa.allowed_purposes == ['appointment_scheduling']
# Vendor SHOULD NOT be able to access PHI for non-scheduling purposes:
vendor_user = User.objects.create(employer='SchedulingVendor')
response = client.get(
'/patient/123/billing',
headers={'Authorization': f'Bearer {vendor_user.token}'},
)
assert response.status_code == 403