SittuAI Editorial

FDA Regulatory Insights

Expert guidance on 510(k), De Novo, PMA submissions, and 21 CFR compliance. Written to help medical device companies navigate FDA regulatory pathways with confidence.

All Articles 510(k) Submissions De Novo Pathway PMA Submissions 21 CFR Compliance FDA Guidance Device Classification Post-Market
510(k) Submissions

Biocompatibility Testing for 510(k): A Complete Submission Guide

Biocompatibility testing for 510(k) submissions requires a risk-based evaluation framework per FDA's 2016 ISO 10993-1 guidance, not a fixed checklist—mistakes in scope, standard application, or data presentation commonly cause 3-6 month delays. Success depends on a robust Biological Evaluation Plan and Report that justify endpoint selection based on device contact type, duration, materials, and lifecycle factors.

11 min read May 16, 2026
Device Classification

How FDA Classifies Medical Devices: Class I, II, and III Explained

**Summary:** FDA classifies medical devices into three risk-based categories that determine the regulatory pathway (510(k), De Novo, or PMA) and oversight required. Correct classification is critical—wrong classification can delay market entry by 12–18 months or trigger enforcement action.

11 min read May 8, 2026
FDA Guidance

Real-World Evidence for Medical Device Regulatory Decisions: An Interpretive Guide

The FDA now accepts real-world evidence (RWE)—data from clinical practice outside controlled trials—to support device approvals, expansions, and postmarket requirements under an evolving regulatory framework. Companies must ensure their real-world data is fit for purpose, methodologically rigorous, and properly documented to meet FDA's credibility standards across the device lifecycle.

11 min read May 8, 2026
FDA Guidance

Device Modifications and the 510(k) Threshold: A Practical Interpretive Guide

Manufacturers of 510(k)-cleared medical devices must determine whether modifications require a new submission or can be documented internally—getting this wrong risks regulatory action or unnecessary delays. FDA's 2017 guidance provides a decision framework based on whether changes "could affect" device safety or effectiveness, placing the burden on manufacturers to document their analysis regardless of outcome.

10 min read May 4, 2026
Device Classification

Classification of Digital Therapeutics: A Practical Guide to Determining Your FDA Regulatory Pathway

Digital therapeutics present a complex FDA classification challenge because software treatments don't fit traditional device categories. Choosing the correct classification pathway—Class I, II, or III—determines your premarket strategy, timeline, and budget, making it the most consequential early-stage regulatory decision.

10 min read Apr 23, 2026
FDA Guidance

FDA Software as a Medical Device (SaMD): A Practical Interpretive Guide

**FDA regulates Software as a Medical Device (SaMD)—software performing medical functions independently on general-purpose platforms like smartphones or cloud servers—under a risk-based framework, with exclusions for administrative tools, wellness apps, and clinical decision support meeting strict criteria. Companies must navigate multiple regulatory instruments including FDA's 2019 AI/ML guidance and 2023 predetermined change control plan guidance to determine premarket clearance requirements.**

10 min read Apr 22, 2026
Device Classification

In Vitro Diagnostic Device Classification: A Practical Guide to Getting It Right

**Summary:** Correct IVD classification determines your regulatory pathway—a Class I exemption takes weeks, Class II 510(k) takes 6–12 months, and Class III PMA takes 18–36 months and millions in costs. The FDA classifies IVDs under 21 CFR Parts 862–892 based on risk level, with each device assigned a product code and class that dictates required evidence, controls, and post-market obligations.

10 min read Apr 20, 2026
510(k) Submissions

Writing a Compelling 510(k) Executive Summary: A Practical Guide

The 510(k) Executive Summary is a critical document that frames FDA reviewers' interpretation of your submission and directly impacts review timelines—a poorly organized summary triggers information requests that can delay clearance 90–180 days. This guide covers mandatory regulatory content, strategic framing, and common errors to distinguish summaries that accelerate clearance from those inviting scrutiny.

10 min read Apr 19, 2026

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