All terms
Simple Agreement for Future Equity
Convertible instrument that converts to equity at a future priced round.
Reviewed by Christian Espinosa, Founder, Blue Goat CyberLast reviewed May 5, 2026
Definition
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. What the regulation says
SAFEs are securities under U.S. federal law and must be issued under an exemption (typically Reg D 506(b) or 506(c)). Form D filings and state blue-sky notices apply.
What this means in practice
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.Examples
- A diagnostics startup raises $2M on a post-money SAFE with a $15M cap to fund an analytical validation study.
- An implant company uses a discount-only SAFE for a strategic angel before its Series A.
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.
Primary references
3 sourcesLink health: 3 verified· last checked 2026-05-09
Y Combinator·1SEC·1NVCA·1
- 1
Y Combinator SAFEVerifiedY Combinatorycombinator.com
- 2
SEC Investor Bulletin: SAFEsVerifiedSECsec.gov
- 3
NVCA Model DocumentsVerifiedNVCAnvca.org
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