Return on investment for mangrove and reef flood protection

•We use risk industry methods to assess returns on investment for reef and mangrove restoration.•Mangrove and reef restoration can be cost effective (B:C > 1) for flood reduction in 20 + Caribbean countries.•Restored natural infrastructure can provide $100,000s/ha in flood protection benefits over project lifetimes.•These rigorous valuations of natural defenses open new opportunities to fund coastal restoration.•Funding from hazard mitigation and disaster recovery sources can support habitat restoration.