FDA Inspections & Warning Letters
US-unique
FDA's direct inspection authority over device manufacturers (domestic and foreign) — and the warning letter system — are distinctly US mechanisms. FDA can inspect without advance notice (announced or unannounced).
Types of FDA device inspections
| Inspection type | Description |
|---|---|
| Surveillance inspection | Routine inspection of registered establishment; periodic (typically every 2 years for Class II/III) |
| Compliance follow-up | After a previous inspection with observations — checks for corrective actions |
| Pre-approval inspection (PAI) | Before FDA approves a PMA; verifies manufacturing processes and data integrity |
| For-cause inspection | Triggered by complaints, MDR trends, or recall activities |
| Unannounced inspection | FDA investigators may arrive without advance notice for domestic manufacturers |
What FDA investigators examine
- QMSR compliance — design controls, CAPA, complaint handling, MDR procedures
- Document and record integrity — are records complete, accurate, and retrievable?
- Manufacturing practices — cleanliness, controlled processes, calibration, environmental monitoring
- Complaint files — are complaints reviewed for MDR reportability?
- Corrective actions — response to previous observations
FDA Form 483 — Inspectional Observations
At the end of an inspection, the FDA investigator may issue FDA Form 483 — a list of observed conditions that may constitute violations. A 483 is not a final determination of violation — it is an observation that the manufacturer must respond to.
Response to 483:
- Respond in writing within 15 business days (longer if needed for complex issues)
- Acknowledge each observation
- Provide specific corrective actions with timelines
- Provide evidence of completed corrections where available