All the Small Things: FDA Warning Letter Highlights the Risks of Unauthorized Device Modifications

Key Takeaways

• FDA issued a Warning Letter to the manufacturer of an infant smart sleeper bassinet for introducing unauthorized modifications, including new sizes and a hospital-use bundle, without submitting required 510(k) premarket notifications or premarket approval applications. Companies should carefully evaluate whether product changes require new marketing authorizations before commercial distribution.
• Expanding a device’s intended use environment (e., from home use to hospital) may constitute a major change in intended use and, therefore, require a new premarket submission.
• The Warning Letter also cited significant quality system deficiencies, including complaint bundling, inadequate design validation, failure to report corrections and removals, and Corrective and Preventative Action (“CAPA”) failures, underscoring that companies with authorized devices must maintain robust post-market compliance programs.

“All the small things, true care, truth brings,” sang Blink-182 and, in the world of medical devices, it is the small things that can bring serious regulatory consequences. The Food and Drug Administration recently issued a Warning Letter to the manufacturer of a smart sleeper bassinet for infants on June 15, 2026, following an inspection of the company’s facility.¹ The bassinet received marketing authorization in March 2023 as the first FDA-authorized infant supine sleep system, classified as a Class II medical device intended for home use by caregivers with three sizes of sleep sacks.²

FDA found that the company introduced unauthorized product modifications, including two new sleep sack sizes and a hospital-use bundle, without submitting required premarket notifications, and cited the company for a range of quality system violations including complaint handling failures, design validation deficiencies, and failure to report corrections and removals. The Warning Letter is a pointed reminder that FDA premarket authorization is only the beginning: what a company does after authorization matters as much. In this Bulletin, we will highlight some key points of the Warning Letter and offer our own observations.

Highlights

Unapproved Device Modifications

• The original marketing authorization specified three sizes of sleep sacks corresponding to defined weight ranges. The company introduced two additional sizes — extra-small for lower-weight infants and an extra-large for higher-weight infants — without submitting a new premarket notification.
  • FDA concluded that the extra-small sleep sack extended the device to a smaller, more vulnerable population not evaluated in the original authorization, constituting both a change that could significantly affect safety or effectiveness and a major change in intended use.
  • FDA found that the extra-large sleep sack may make it easier for an infant to break free and assume an unsafe position within the bassinet.
• According to 21 C.F.R. § 807.81(a)(3), a manufacturer must submit a new 510(k) before distributing a device that has been changed in a manner that could significantly affect safety or effectiveness, or that constitutes a major change in intended use. This requirement applies equally to De Novo-authorized devices.

Change of Intended Use Environment

• FDA’s authorization specified the bassinet for “home use by caregivers.” The agency found that the company was marketing a hospital bundle which included the bassinet, a mobility cart, and additional accessories for use in clinical settings without a new premarket submission.
  • The hospital setting introduces risks not evaluated in the original authorization, including infection control requirements, medically complex infant populations, and a mobility cart whose wheel lock failure could result in the device rolling or tipping while an infant is inside.
  • The company argued the hospital version was marketed “exclusively as a soothing tool” and was, therefore, not a “medical device.” FDA rejected this argument, concluding the product’s intended use remained to facilitate a supine sleep position.

Quality System and Post-Market Violations

• FDA cited the company for “bundling” multiple distinct complaints into single records, rather than evaluating each complaint individually for medical device reporting (“MDR”) and CAPA triggers.
• Design validation testing was performed using only an average-sized model infant, despite the device being authorized for use across a range of weights.
• Customers received refurbished bassinets that were stained, soiled, or unsanitary. The company sent replacements but failed to report the action to FDA under 21 C.F.R. Part 806 as a correction or removal initiated “to reduce a risk to health posed by the device.”
• FDA warned that failure to address the violations may result in seizure, injunction, or civil money penalties, and noted that corrective actions must comply with the QMSR requirements effective February 2, 2026.³

AGG Observations

• FDA marketing authorization is a starting line, not a finish line. Companies should build post-authorization compliance into their regulatory strategies from day one.
• When considering modifications to medical devices, manufacturers should consult 21 C.F.R. Part 807, FDA guidance, enforcement trends, and relevant predicate device clearances when evaluating whether a modification triggers new authorization. In particular, manufacturers should apply a risk-based, decision-tree analysis consistent with FDA’s 2017 guidance document, “Deciding When to Submit a 510(k) for a Change to an Existing Device.⁴ AGG has previously written Bulletins about this guidance.⁵
• Even seemingly minor product modifications must be evaluated prior to commercial distribution. For example, adding a size variant may seem like a routine product line extension but, when the original authorization specifies particular configurations, any change to those specifications can cross the regulatory threshold. Manufacturers should document their modification assessments thoroughly and, when in doubt, engage with FDA before introducing changes. If the company decides to proceed without a new submission, it should document its rationale in a memo to file. While such documentation may not prevent FDA enforcement, it demonstrates a good faith attempt at compliance and may mitigate the degree of enforcement.
• Companies considering new use settings for their medical devices should consider submitting new premarket submissions before marketing into those environments, not after FDA raises questions. For example, expanding from home use to hospital use is not a product accessory decision. According to the agency, it is a major change in intended use. The hospital setting introduces distinct risks, including infection control protocols, medically fragile patient populations, and equipment mobility concerns, none of which were evaluated in a home-use authorization.
• FDA discovered these modification issues during an inspection, and not seemingly through a review of product promotion. The agency has many ways it can detect noncompliance.
• Companies transitioning from consumer products to regulated medical devices must fully internalize medical device quality system requirements. The practice of “bundling” multiple complaints into a single record reflects a consumer-product mindset that is incompatible with FDA’s expectations. Each complaint must be individually evaluated for Medical Device Reporting obligations, CAPA triggers, and trending. Bundling can mask safety signals and undermine the analyses that quality systems rely on to identify emerging risks.
• Design validation should test the full range of intended users, not only the average case. When a device is authorized for use across a range of infant weights, validation protocols should reflect the full diversity of that population, including boundary conditions at the extremes of any specified range.
• Product replacement and refurbishment programs can trigger correction and removal reporting obligations under 21 CFR Part 806. When a manufacturer sends replacement devices to address quality complaints that action may meet the regulatory definition of a correction or removal initiated to reduce a risk to health. Companies must evaluate field actions under Part 806 and report within 10 working days. Treating a product swap as routine customer service, without assessing the regulatory implications, can result in misbranding charges.
• With the QMSR now in effect as of February 2, 2026, companies should use enforcement actions like this Warning Letter as an occasion to audit their own quality systems against the new requirements. The QMSR incorporates ISO 13485:2016 by reference, harmonizing FDA’s framework with international standards. Companies operating under the prior QSR should confirm their systems satisfy the updated requirements and be prepared for inspections under FDA’s revised compliance program.

In sum, device manufacturers should take note of the Warning Letter’s lessons. Small changes can create big problems, so even minor device modifications should be assessed with the same regulatory rigor as the original submission. By “sweating the small stuff” — thoroughly evaluating product changes, maintaining strong quality systems, and submitting required premarket filings before implementing modifications — manufacturers can minimize unwelcome regulatory wake-up calls.

For guidance on these issues, please contact a member of AGG’s Food & Drug team.

[1] The Warning Letter can be found here.

[2] FDA granted the De Novo classification request (DEN210039) on March 30, 2023.

[3] The QMSR, effective February 2, 2026, amends 21 CFR Part 820 by incorporating ISO 13485:2016 by reference. Additional information can be found here.

[4] FDA’s guidance, “Deciding When to Submit a 510(k) for a Change to an Existing Device,” can be found here, last revised on October 25, 2017.

[5] See AGG Bulletins dated August 12, 2016, and August 18, 2016