Clinician sees failed logons
On next EHR login, RN is notified of three overnight unsuccessful attempts — reports possible attack.
Unsuccessful Logons
Medium Risk
Easy
Low Cost
AC-9(1) enhances AC-9 by focusing on unsuccessful logons. Notify users of unsuccessful logon attempts since last successful logon on EHR/VPN to help detect credential attacks against clinical accounts. Covered entities and business associates should implement this with clear ownership, technical enforcement where feasible, and audit evidence aligned to HIPAA Security Rule expectations.
Control Objective
Notify the user of unsuccessful logon attempts to ePHI systems since the last successful logon.
Implementation Guidance
- Enable unsuccessful logon notices on EHR/VPN portals.
- Show attempts since last successful logon.
- Provide reporting contact for suspicious notices.
- Avoid leaking whether usernames exist to anonymous users.
- Ensure notice binds to the authenticated user.
- Log that notices were displayed if feasible.
- Educate workforce to report unexpected failures.
- Validate after SSO changes.
Real-World Use Cases
How this control shows up in healthcare and HIPAA-covered environments.
VPN failure notice
Remote coder sees unsuccessful VPN tries since last success and resets MFA device.
Shared-device clarity
Message distinguishes unsuccessful attempts on the user's account, not the workstation's prior users.
Best Practices
- Tie AC-9(1) to named owners in IAM/privacy/security.
- Prefer system enforcement over informal email approval.
- Measure coverage on systems that store or transmit ePHI.
- Review exceptions at least quarterly.
- Correlate events into SIEM use cases.
- Document mapping to HIPAA safeguards in the SSP.
Common Gaps & Violations
- Policy claims unsuccessful logons but no technical enforcement on EHR paths.
- Exceptions granted permanently without review.
- Vendors and research feeds left out of scope.
- Logs not retained or not reviewed.
- Upgrades silently disable the control.
Required Documentation
- Policy/procedure for Unsuccessful Logons (AC-9(1))
- Configuration baselines and diagrams
- Exception register
- Sample logs/alerts
- Training or runbook evidence
How to Test & Validate
- Attempt a prohibited action related to unsuccessful logons; confirm block or required workflow.
- Complete an authorized path; confirm success and logging.
- Sample exceptions for expiry and approval.
- Verify ePHI systems in scope are covered (not only corporate IT).
- Confirm SIEM/alert or retention evidence for the last 90 days.
Audit Considerations
Assessors look for operating evidence of Unsuccessful Logons on systems touching ePHI — screenshots, logs, and failed-test results — not only a policy paragraph referencing AC-9(1).
HIPAA Mapping
How this NIST control supports HIPAA Security Rule expectations.
- 164.308(a)(5)(ii)(C) Log-in Monitoring — procedures for monitoring log-in attempts.
- 164.312(b) Audit Controls — record and examine access activity.
- 164.312(d) Person or Entity Authentication — detect misuse of credentials.
- 164.308(a)(6) Security Incident Procedures — user notices can trigger early incident reporting.
Compliance Tips
- List AC-9(1) explicitly in the system security plan control matrix.
- Prioritize EHR, VPN, HIE, and BA file-transfer paths.
- Keep a one-page evidence pack (config + sample log + exception list) ready for assessors.
Frequently Asked Questions
Does this replace SIEM?
No — user notification complements centralized log-in monitoring.
Privacy of notices?
Do not display details that help attackers (e.g., whether username exists) beyond the account owner session.
Shared workstations?
Ensure notice is for the authenticated user account.
References & Resources
- NIST SP 800-53 Rev. 5 — AC-9(1)
- Related controls: AC-9, AC-7, AU-2
Related Guidelines
Related controls that commonly accompany AC-9(1).
Need Help Implementing AC-9(1)?
Our auditors map NIST SP 800-53 controls to your HIPAA Security Rule program — policies, technical evidence, and audit readiness.