The FDA has now finalised its guidance on Human Factors information in marketing submissions (May 2026), building on the long-standing 2016 Human Factors Guidance (Applying Human Factors and Usability Engineering to Medical Devices) 

At first glance, it might feel like a formality, just an administrative update. But it isn’t. What we’re seeing is a clear shift in the FDA’s perspective from: “Show us you did Human Factors properly” to “Show us the right level of Human Factors evidence – based on risk.” And that has practical consequences for anyone designing medical devices or running HF programmes. 

1. The big shift: from process guidance → submission strategy 

The 2016 guidance is fundamentally about how to do Human Factors well: 

• Identify users, environments, interfaces 

• Understand use-related hazards 

• Define critical tasks 

• Design out risk 

• Validate through testing 

It is deeply rooted in design and risk management. The new 2026 guidance doesn’t replace that, it sits alongside it. Instead, it focuses on: 

• What HF information you need to submit 

• When you need full validation evidence 

• How to justify doing less (when appropriate) 

In other words: 

• 2016 = Do the work 

• 2026 = Show the right amount of that work 

2. A risk-based lens on everything 

The most important addition is the move to a formal risk-based framework. The FDA now expects manufacturers to decide: How much HF evidence is appropriate for this device and this change? The decision on how much evidence is required is guides via the HF Submission Categories (1, 2, 3): 

• Category 1: high-level summary 

• Category 2: limited evidence 

• Category 3: Full HF validation report required 

Which category is appropriate to your device is determined by whether the new design: 

• Creates or changes critical tasks 

• Impacts on user interaction 

• Changes the Complexity of the interface 

• Impacts the Adequacy of risk controls 

This builds directly on the 2016 concept that critical tasks are defined by potential for serious harm. 

The difference is that: 

• Previously: identifying critical tasks drove design and testing 

• Now: it also directly drives regulatory evidence expectations 

3. The quiet but important elevation of URRA 

The new guidance formally centres Use-Related Risk Analysis (URRA) as the decision engine. You can see this in how it’s used to: 

• Determine whether critical tasks exist or are impacted

• Support whether validation testing is needed 

• Justify what is (or isn’t) submitted 

This links tightly back to the 2016 workflow: 

• Identify hazards 

• Identify critical tasks 

• Apply risk controls 

• Validate effectiveness 

What’s changed is emphasis: 

• URRA is no longer just “good HF practice” 

• It’s now a regulatory decision tool 

4. Validation testing is still central, but no longer automatic 

The 2016 guidance is clear: 

• Human factors validation testing is used to demonstrate safe and effective use 

• It must include all critical tasks 

• It should identify use errors that could cause harm 

That hasn’t changed. But the new guidance introduces an important nuance; you may not need to submit validation testing, if you can justify why. This is particularly relevant where: 

• The interface has a strong history of safe use 

• The design change doesn’t impact critical tasks 

• Risk controls remain adequate and unchanged 

Practically:

• HF validation doesn’t disappear 

• But the burden of evidence becomes contextual 

5. “Critical tasks” now drive regulatory outcomes, not just HF studies 

In the 2016 guidance: 

• Critical tasks are used to:  

• Focus design effort 

• Structure validation testing 

In the 2026 guidance:

• Critical tasks now determine:  

• Submission category

• Level of required evidence 

• Need for validation testing 

This is a subtle but important shift:

• Critical tasks are no longer just a study design tool 

• They are now a regulatory decision hinge 

6. The growing importance of justification (not just data) 

One of the biggest behavioural changes is this: 

You now need to be able to explain: 

• Why something isn’t a critical task 

• Why a change doesn’t impact user interaction 

• Why validation testing isn’t necessary 

  
  

And those justifications must be grounded in:

• URRA 

• Comparison to existing devices 

• Known use problems 

• Interface complexity and user familiarity 

In practice, this means:

• Narrative quality matters more than ever 

• HF isn’t just about generating data, it’s about defending decisions 

7. Nothing relaxes expectations on safety

It’s worth being clear: this is not deregulation. Both guidance documents reinforce that: 

• The goal is still elimination or reduction of use-related risk 

• Devices must be safe and effective for intended users and environments 

And critically:

• Residual risk must still be analysed and justified 

The FDA is not lowering the bar, it’s making expectations more structured and explicit. So what does this mean for HF teams (and device manufacturers)? 

1. Your URRA needs to be robust and defensible 

It’s now doing double duty: 

• Driving design decisions 

• Driving regulatory strategy 

2. “Minor changes” need evidence-backed justification 

You can’t just say “This won’t impact users” You have to show: 

• Why it doesn’t affect perception, cognition, or action 

• Why critical tasks remain unchanged 

3. HF strategy needs to be aligned with regulatory strategy early 

HF can no longer be just a late-stage validation activity. It influences: 

• Submission pathway 

• Evidence expectations 

• Project timelines 

4. Validation testing is more strategic 

Not everything needs full testing, but if you don’t test, you need a strong case why. 

5. Documentation quality becomes a differentiator 

The difference between Category 2 and Category 3 
often comes down to how well you can argue your case. 

Final thought 

If the 2016 guidance taught the industry how to do Human Factors, 
the 2026 guidance teaches it how to justify Human Factors decisions. 

And that’s a quiet but significant evolution. It shows how HF in medical devices is maturing, because increasingly, success isn’t just about doing the right work, 
it’s about being able to explain, defend, and scale that work appropriately.