A SAFE is a financing contract created by Y Combinator in 2013 that gives investors the right to receive shares in a future priced equity round, typically at a discount and/or subject to a valuation cap. Unlike convertible notes, SAFEs carry no interest rate and no maturity date. Since 2018 the standard YC SAFE is post-money, which makes the holder's ownership easier to calculate before the priced round. A SAFE converts when a priced equity round occurs, and has specific terms for a sale or dissolution before conversion. Stacking many SAFEs can produce surprising dilution, so founders should model conversion in the cap table.

Why it matters

Early-stage MedTech companies often raise seed capital through SAFEs to defer the valuation discussion until clinical or regulatory milestones (first-in-human, 510(k) submission, CE mark) materially de-risk the company. Stacking many SAFEs without modeling dilution at conversion is a frequent founder mistake.

Common pitfalls

•Confusing pre-money and post-money SAFEs - post-money SAFEs guarantee the investor's ownership percentage and are far more dilutive at conversion.
•Issuing too many SAFEs with different caps, creating a 'SAFE stack' that surprises founders at the priced round.

Sources

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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.

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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.