Attachment Point
Definition
The attachment point is the level at which an insurance-linked security or reinsurance layer begins to pay losses. Below it, the sponsor retains losses; above it, investors' principal is used until the exhaustion point. Depending on the trigger, the attachment point is a dollar amount of the sponsor's losses (indemnity), a value of an industry index, a modeled loss, or a physical threshold such as a hurricane's central pressure in a defined box.
Why it matters
The attachment point decides how often a layer pays and therefore much of its price. It is only meaningful together with the trigger, the exhaustion point and the modeled probabilities: two bonds attaching at the same dollar figure can have very different risk if one covers Florida wind and the other European storm.
Common misconceptions
- •Attachment point is not expected loss; it is a threshold.
- •A modeled one-in-100-year attachment does not mean losses can only happen once a century.
- •Attachment can move after issue if index estimates are revised or reset provisions apply.
- •The label is only a starting point. Investor outcomes usually depend on the governing documents, cash-flow priority, valuation policy, disclosure quality, and manager discretion surrounding the term, not just the shorthand definition used in marketing materials.
Technical details
By trigger type
Indemnity: the sponsor's ultimate net loss above a retention (Allstate: $1.00 billion per occurrence).
Industry index: an index value (Swiss Re example: EUR 2.0 bn PERILS).
Parametric: physical thresholds by box (Jamaica: central pressure per box, with 30%, 70% and 100% payout steps).
Modeled loss: a modeled amount for the sponsor's portfolio.
Reading it with the statistics
Attachment probability: chance the layer is hit in a year.
Exhaustion probability: chance it is fully used.
Expected loss: average annual loss, between the two.
Return period: one divided by the annual probability (2.46% is about 1 in 41 years).
How investors apply the term
Investors usually apply this term by tying the definition back to the controlling documents and then asking which cash flows, rights, restrictions, or valuation assumptions it changes. A useful review looks at the term alongside fees, leverage, liquidity, reporting frequency, and manager discretion rather than treating it as a standalone concept.
The practical diligence test is simple: identify who benefits if the assumption is wrong, who has control when conditions change, and what evidence the investor receives after closing. Terms that cannot be reconciled to documents, cash movements, and monitoring data should be treated as marketing shorthand until proven otherwise.
Frequently asked questions
- What does an attachment point look like in practice?
- In Allstate's 2025 nationwide program, the per-occurrence cover applies to losses 'up to $9.51 billion of loss less a $1.00 billion retention'; layers above attach at higher levels. In Swiss Re's 2011 PERILS example, investors start losing principal at EUR 2.0 bn of industry losses.
- How likely is a layer to attach?
- That is the attachment probability, which modeling firms estimate. Jamaica's 2024 cat bond had an annual attachment probability of 2.46%; Chile's 2023 bond 1.48%, per World Bank case studies.
- Does a higher attachment point always mean less risk?
- It means losses reach the layer less often. But Swiss Re notes 'cliff risk,' the likelihood that a tranche's notional 'will quickly be exhausted once losses in the portfolio reach the attachment point.'