MFDS Adverse Event Reporting: 5-Day, 15-Day, and 30-Day Deadlines Explained
Korean adverse event reporting timelines are among the strictest globally. Missing a deadline can trigger product suspension. Here's the complete reporting framework.
The 3 Reporting Timelines
Timeline 1: 5-Day Reporting (Fatality or Imminent Death Risk)
Required when:
- Patient death
- Serious injury that could result in death
- Public health risk requiring immediate attention
Clock starts: When KLH first becomes aware of the event.
Filing: Preliminary report via MFDS electronic system within 5 calendar days.
Follow-up: Detailed investigation report within 30 days.
Timeline 2: 15-Day Reporting (Serious Adverse Events)
Required when:
- Serious injury (hospitalization, surgical intervention, prolonged recovery)
- Permanent impairment
- Congenital anomaly
- Event requiring medical intervention to prevent serious injury
Clock starts: When KLH first becomes aware.
Filing: Report via MFDS electronic system within 15 calendar days.
Follow-up: Investigation update within 30 days.
Timeline 3: 30-Day Reporting (Other Reportable Events)
Required when:
- Device malfunction with potential for serious harm (even if no harm occurred)
- Recurring nuisance events suggesting design issue
- Field safety corrective actions (FSCA) initiated outside Korea
Clock starts: When KLH first becomes aware.
Filing: Report within 30 calendar days.
Decision Tree: Which Timeline?
Did event involve:
├── Death or imminent death risk?
│ └── YES → 5-Day Reporting
├── Serious injury or permanent impairment?
│ └── YES → 15-Day Reporting
└── Malfunction or other reportable event?
└── YES → 30-Day Reporting
Who Is Responsible
| Entity | Responsibility |
|---|---|
| KLH (Korea License Holder) | Files reports with MFDS, primary regulatory contact |
| Manufacturer | Supplies investigation data, root cause analysis, CAPA |
| Distributor (if separate from KLH) | Reports events to KLH within 24 hours of awareness |
| Healthcare provider | Reports events to KLH or directly to MFDS |
| Patient | Can report directly to MFDS (less common) |
The Critical 24-Hour Window
While MFDS reporting deadlines are 5/15/30 days, the internal 24-hour window is operationally critical:
- Distributor or healthcare provider reports event
- KLH receives notification
- KLH must trigger investigation immediately
- Investigation determines reporting timeline (5/15/30 days)
- Clock has already started from KLH first awareness
Operational implication: Late distributor-to-KLH reporting can put KLH outside MFDS deadline before investigation begins.
Common Reporting Failures
Failure 1: Misclassified Severity
Event classified as "30-day" when it should be "15-day" or "5-day."
Risk: Late report = potential regulatory action.
Fix: Conservative classification when uncertain; consult Korean clinical advisor.
Failure 2: Distributor-to-KLH Delay
Distributor sits on event for 5–10 days before notifying KLH.
Risk: KLH outside MFDS deadline before they know event exists.
Fix: Distributor agreement requires 24-hour notification with penalties for delay.
Failure 3: Investigation Pending Excuse
"We need more time to investigate."
Reality: MFDS deadlines do not wait for complete investigation. Preliminary report required by deadline; investigation update follows.
Fix: File preliminary report on time; follow up with detailed investigation.
Failure 4: Underreporting "Minor" Events
Manufacturer judges event as too minor to report.
Risk: Pattern of minor events may signal design issue; MFDS audit reveals unreported events.
Fix: When in doubt, report. Better to over-report than face audit finding.
Failure 5: No Korean Translation
Investigation reports in English only.
Risk: MFDS may not accept; deadline missed.
Fix: Korean translation of report (full or executive summary) before submission.
Required Report Contents
5-Day Preliminary Report
Minimum content:
- Event description (Korean)
- Device identification (KMD number, lot, serial)
- Patient information (anonymized)
- Healthcare provider information
- Date of event awareness
- Preliminary assessment
- Investigation plan
15-Day Report
All of the above plus:
- More detailed event description
- Clinical context
- Preliminary causality assessment
- Immediate corrective actions (if any)
30-Day Report
All of the above plus:
- Investigation results (if available)
- Root cause analysis (preliminary)
- CAPA initiated
30-Day Follow-Up (for 5/15-day reports)
- Full investigation report
- Root cause analysis
- CAPA implementation
- Recurrence prevention plan
Operational Setup for KLH
To meet MFDS deadlines, KLH operations require:
People
- Dedicated vigilance contact at KLH (24/7 availability for 5-day events)
- Manufacturer regulatory contact (24-hour response)
- Korean clinical advisor (on-call for severity classification)
Process
- Event intake procedure (multiple channels: phone, email, electronic form)
- Severity classification within 24 hours of receipt
- Report drafting workflow with Korean translation
- MFDS electronic submission capability
Documentation
- Event log with all reportable events
- Decision rationale for each classification
- MFDS submission confirmation receipts
- Investigation reports archived 5+ years
What Triggers MFDS Action
MFDS may take action when:
- Pattern of late reporting (multiple events in audit period)
- Severe under-classification (5-day events reported as 30-day)
- Investigation reports incomplete or inadequate
- CAPA not implemented or ineffective
- Recurring events without effective intervention
Typical actions:
| Severity | MFDS Action |
|---|---|
| Minor | Warning letter |
| Moderate | License conditions added |
| Severe | License suspension |
| Critical | Import ban + recall |
Frequently Asked Questions
Q: What if we discover an event from old records (1+ years ago)?
A: Report immediately upon discovery with explanation of late discovery. MFDS expects timely reporting from awareness date, not event date.
Q: Do we report events from other countries?
A: Yes, if (a) same device is sold in Korea, (b) event suggests safety concern affecting Korean market, or (c) field safety corrective action is initiated globally.
Q: Can MFDS waive reporting deadlines?
A: Rarely. Waivers typically only for documented force majeure (natural disasters, etc.).
Q: How does Leanabl support vigilance?
A: Leanabl's Vigilance & Post-Market Reporting service handles MFDS vigilance operations end-to-end, including event intake, classification, reporting, and CAPA coordination.
Q: What's the difference between vigilance and PMS?
A: Vigilance is reactive (reporting adverse events). PMS (post-market surveillance) is proactive (monitoring product performance over time). Both are required.
How Leanabl Helps
- Vigilance & Post-Market Reporting — full MFDS vigilance operations
- Korea Post-Market Operations — portfolio-wide post-market management
- KLH Service — vigilance handled through independent KLH
Contact Leanabl for vigilance scoping.
Last updated: 2026-05-15.
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