Also known as: attachment point insurance · attachment point vs deductible
The dollar amount of loss at which an excess or reinsurance layer starts to pay, once the coverage beneath it is used up.
The attachment point is the loss level where a particular layer of coverage begins to respond. Below it, the primary policy, a self-insured retention, or a lower excess layer pays; the excess or reinsurance layer only 'attaches' once losses climb above that threshold. For a startup buying an excess or umbrella tower over a $1M primary D&O or Tech E&O policy, the first excess layer usually has a $1M attachment point, so it pays only after the underlying limit is exhausted. Getting each attachment point to line up with the limit below it is what prevents gaps in the tower where no policy responds.
An attachment point is the amount of loss at which a specific layer of coverage begins to pay. Everything below it is covered by an underlying policy, a retention, or a lower excess layer, and the layer in question only responds once losses exceed that point. It is the key number that stitches a primary policy and its excess layers into a single coverage tower.
Both describe a threshold before coverage responds, but they sit in different places. A deductible or retention is the amount you pay out of pocket on your primary policy, while an attachment point is the loss level at which an excess or reinsurance layer starts paying above the underlying insurance. In a layered program you can have both: a retention at the very bottom and attachment points between each excess layer.
For a typical excess policy, the attachment point equals the total limit of the coverage sitting directly beneath it. If your primary D&O policy carries a $1M limit, the first excess layer usually attaches at $1M and pays only after that $1M is exhausted. Each additional layer attaches at the combined limits of everything below it.
Definitions are educational and may be modified by your specific policy language, endorsements, and state rules. For regulatory guidance, refer to the California Department of Insurance or the NAIC.
Last updated: July 2026.