E&S (excess and surplus lines) (definition)
The non-admitted market where risks the standard market declines are written, with freedom of rate and form and without state guaranty fund backing.
Excess and surplus lines is the non-admitted side of the market: coverage written by insurers not licensed (admitted) in the insured’s state, accessed through surplus lines brokers, for risks the standard market will not write at acceptable terms.
The trade is flexibility for protection. E&S carriers have freedom of rate and form, so they can craft terms for hard-to-place risks. In exchange, policies are not backed by the state guaranty fund and rate and form filings do not apply.
For agencies, E&S placement usually runs through a wholesale broker and brings its own mechanics: surplus lines taxes, diligent-search requirements where they still apply, and disclosure obligations to the insured.