Medical Device Warning Letters Doubled. Here Is What Changed and Why It Matters.

In fiscal year 2025, the FDA issued 44 Warning Letters to medical device manufacturers.

That number is more than double the average from the late 2010s and early 2020s, when annual totals ranged between 11 and 21. Of those 44 Warning Letters, 38 cited violations of the Quality System Regulation under 21 CFR 820. Eleven more than the prior fiscal year.

The data tells a clear story. The FDA is reasserting its enforcement posture in the medical device space, and the Quality System Regulation is the agency's primary tool.

With the new Quality Management System Regulation (QMSR) taking effect on February 2, 2026, manufacturers are operating in a transition period where the regulatory expectations are simultaneously becoming stricter and more complex.

Medical device brands that have not modernized their quality systems are entering 2026 with a target on their back.

The Numbers Behind the Enforcement Surge

FDA inspection data from 2025 shows the agency moved from a quiet January, where no Warning Letters were issued during a leadership transition, to an aggressive pace by mid-year. By early September 2025, the agency had already issued 19 Warning Letters citing Quality System Regulation violations, surpassing the same period in 2024.

Investigators are using artificial intelligence tools to analyze complaint data, adverse event reports, and historical inspection outcomes. Manufacturers with unresolved corrective and preventive actions (CAPAs) or inconsistent documentation are being flagged earlier and inspected more often. Many recent Warning Letters include explicit commitments to follow-up inspections, signaling a shift toward continuous oversight rather than one-time enforcement.

The FDA is also issuing more untitled letters, including some where the agency has not identified any inadequacies in a Form 483 response. These untitled letters carry a 30-workday response requirement and often signal that products are deemed adulterated or misbranded, even without rising to the threshold of a Warning Letter.

What the QMSR Transition Means for Manufacturers

The Quality Management System Regulation, effective February 2, 2026, harmonizes FDA quality system requirements with ISO 13485:2016. Although the official compliance date has arrived, FDA investigators have been informally benchmarking quality systems against ISO standards for the past year. Manufacturers who waited for the deadline to begin transitioning are already behind.

Key areas of inspector focus include:

•        Risk management integration throughout the design, production, and post-market surveillance process.

•        Documented evidence that corrective and preventive actions are not just opened, but closed with verified effectiveness.

•        Supplier controls that include verification, qualification, and ongoing monitoring.

•        Design controls that demonstrate traceability from user needs through verification and validation.

•        Complaint handling and post-market surveillance systems that feed back into the quality system.

The Most Common Quality System Violations Cited

in Warning Letters

Reviewing the 38 Quality System Regulation Warning Letters issued in fiscal year 2025, several patterns emerge. These are the violations manufacturers are most often cited for:

Violation Area	21 CFR 820 Citation	Common Manifestation
CAPA failures	820.100	CAPAs opened but never closed, or closed without verification of effectiveness
Complaint handling	820.198	Failure to investigate complaints, or to evaluate them for MDR reporting
Design controls	820.30	Inadequate design validation, missing design history file documentation
Production controls	820.70	Process validation gaps, environmental control failures
Purchasing controls	820.50	Inadequate supplier evaluation, qualification, and ongoing monitoring

Personal Liability Is Back on the Table

Medical device manufacturers should pay close attention to a parallel trend in 2025: the increasing use of individual criminal prosecutions against device executives. Several individual device-related criminal prosecutions in 2025 have underscored that personal liability for violations of the Federal Food, Drug, and Cosmetic Act is not theoretical.

Former Aesculap regulatory affairs specialist Peter Stoll III was sentenced to one year in prison and ordered to pay more than $122,000 in restitution after pleading guilty to introducing adulterated and misbranded devices into interstate commerce. The case included allegations of forging FDA clearance letters.

Compliance failures are no longer just a corporate financial risk. They are a personal legal risk for executives, regulatory affairs leaders, and quality system owners.

What Medical Device Brands Should Do Now

With the QMSR effective and the FDA enforcement pace elevated, manufacturers should be moving on three fronts simultaneously:

1.     Conduct a QMSR gap assessment. Even manufacturers with mature quality systems should not assume their current procedures fully align with ISO 13485:2016 expectations under the QMSR. A formal gap assessment identifies the documentation and process changes needed before an FDA inspection.

2.     Audit your CAPA system. If CAPAs are sitting open, or closing without verification of effectiveness, that is the single most common citation in recent Warning Letters. Review every open CAPA, document closure justifications, and confirm effectiveness checks are in place.

3.     Strengthen supplier controls. The FDA increasingly expects manufacturers to verify, qualify, and monitor their suppliers on an ongoing basis. A one-time supplier qualification document is no longer sufficient.

How Bustos Law Group Supports Medical Device Manufacturers

Bustos Law Group works with medical device companies on the full range of FDA regulatory issues, from pre-submission strategy through post-market enforcement response. The firm provides QMSR transition support, Warning Letter response strategy, 510(k) submission guidance, and comprehensive compliance reviews.

With FDA enforcement activity at its highest level in years and personal liability risks expanding, medical device executives need experienced counsel to navigate the regulatory landscape. Schedule a consultation with Bustos Law Group to assess your compliance posture and prepare for the next inspection.