The Quality System Regulation (21 CFR Part 820) sets out the cGMP requirements that govern the methods used in, and the facilities and controls used for, the design, manufacture, packaging, labeling, storage, installation, and servicing of finished medical devices intended for human use. The QSR was a flexible umbrella regulation: it told manufacturers what their quality system had to cover, such as management responsibility, design controls, purchasing, production and process controls, CAPA, complaints and records, without prescribing exactly how. On February 2, 2026, it was replaced by the Quality Management System Regulation (QMSR), which aligns Part 820 with ISO 13485:2016. Older warning letters and guidance still cite QSR sections.

Why it matters

FDA has harmonized the QSR with ISO 13485:2016 in the Quality Management System Regulation (QMSR), which becomes effective in 2026. Manufacturers must align procedures with the new framework.

Common pitfalls

•Misinterpreting "harmonization" to mean identical, as there will still be FDA-specific requirements in the QMSR beyond ISO 13485:2016.
•Failing to adequately document design control activities, leading to challenges during FDA inspections.
•Assuming that compliance with ISO 13485:2016 automatically means full compliance with 21 CFR Part 820 without addressing FDA-specific nuances. Quality System Regulation (21 CFR Part 820) compliance is mandatory for medical devices marketed in the United States, while ISO 13485:2016 is a globally recognized voluntary standard that often satisfies QSR requirements.
•Neglecting to update quality system procedures and training to reflect the specific requirements of the Quality System Regulation (21 CFR Part 820) when operating in the US market, even if compliant with other international standards.
•Underestimating the importance of robust complaint handling and medical device reporting (MDR) as outlined in 21 CFR Part 820 Subpart M, which are critical for post-market surveillance.

Sources

Quality System Regulation (21 CFR 820) · eCFR
FDA - Quality Systems · FDA
ISO 13485 Standard Page · ISO

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Why compare MedTech terms side by side?

MedTech terminology is full of pairs that look interchangeable but carry very different regulatory, clinical, and commercial consequences. Picking the wrong framework, pathway, or standard early in a project can add months to a submission, invalidate clinical evidence, or trigger an audit finding. Side-by-side comparison is the fastest way to surface those differences before they become costly mistakes.

Each comparison on this page pulls from the same vendor-neutral, sourced definitions used throughout the MedTech Terms glossary. You see the one-line summary, the formal definition, why it matters in practice, common pitfalls, and the primary sources (FDA guidance, EU MDR/IVDR articles, ISO/IEC standards, MDCG documents, IMDRF principles) that back each entry. That makes the comparison defensible in regulatory strategy memos, design reviews, and submission narratives.

Common comparison patterns

Regulatory pathway choice - 510(k) vs PMA, 510(k) vs De Novo, Abbreviated vs Special 510(k).
Quality systems - QSR vs ISO 13485, QMSR vs QSR.
Software classification - SaMD vs SiMD, Locked vs adaptive AI.
EU frameworks - MDR vs IVDR, CE Mark vs UKCA.
Cybersecurity artifacts - SPDX vs CycloneDX SBOM, CVE vs CVSS.
Post-market actions - Recall vs field action, Removal vs correction.

How to use this tool

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MedTech Terms is a vendor-neutral community resource sponsored by Blue Goat Cyber. Definitions are written for educational use and are not legal or regulatory advice.