Glossary

Duty to defend

A liability insurer's obligation to pay for your defense of a lawsuit that could potentially fall within coverage, which is broader than its duty to pay.

Also called: insurer's duty to defend, right and duty to defend, defense obligation

The duty to defend is the insurer's promise to hire and pay lawyers when you are sued over something the policy might cover. The ISO CGL (CG 00 01) gives the insurer the right and duty to defend any suit seeking covered damages, and says there is no duty when the suit seeks damages the policy does not cover. The duty ends when the insurer has used up the limit paying judgments or settlements.

In most states, the test is whether the allegations in the complaint, read against the policy, potentially fall within coverage. This is often called the eight corners or four corners approach. If any claim could be covered, many states require the insurer to defend the whole suit, including the parts that are groundless or excluded. A few states let a court look at facts outside the complaint. Because the trigger is possibility, not proof, this duty is wider than the duty to indemnify.

Practical points: send the suit papers to the insurer at once, since late notice can complicate things. The insurer may defend under a reservation of rights letter, and in some states a conflict entitles you to independent counsel. Do not settle, admit liability or pay on your own, or you may lose coverage under the voluntary payments condition.

the insurer's duty to defend: what triggers it and when it ends covers the state-by-state differences in depth.

Last reviewed October 10, 2026

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Related terms

Duty to indemnify The insurer's obligation to pay a covered judgment or settlement against you, decided on the facts established rather than the complaint's allegations. Reservation of rights An insurer's written notice that it is handling a claim or defending a suit while keeping the right to deny coverage or recover costs later. Defense costs The attorney fees, expert fees and other expenses of fighting a claim, which some policies pay on top of the limit and others deduct from it. Occurrence In liability insurance, the event that triggers coverage and determines which limit and deductible apply; the ISO CGL form defines it as an accident. Claims-made policy A liability policy that covers claims first made against you and reported to the insurer during the policy period, whenever the underlying act occurred.

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Endosos de asegurado adicional, explicados Qué hace cada endoso CG 20 10, CG 20 37, CG 20 26 y CG 20 38, cómo la edición 04 13 limita la cobertura y por qué el certificado no es el endoso. Seguro de responsabilidad civil general: qué cubre y qué no Paga lesiones y daños a terceros y reclamos por publicidad, y defiende la demanda. Qué excluye el formulario ISO y qué determina el precio.