Glossary
Additional insured
A person or business added by endorsement to someone else's liability policy so it can claim directly for suits tied to the policyholder's work or premises.
Also called: AI, additional insured endorsement, additional named insured
An additional insured is a party that is not the policyholder but gains insured status on the policyholder's liability policy through an endorsement. Landlords, general contractors, property owners and clients ask for it in contracts so they can tender a claim to your insurer instead of chasing you.
On a commercial general liability policy the usual ISO forms are CG 20 10 (ongoing operations) and CG 20 37 (completed operations) for contractors, CG 20 11 for managers or lessors of premises, and CG 20 26 for a designated person or organization. The 04 13 editions cover the additional insured only for injury or damage caused in whole or in part by the named insured's acts or omissions, only to the extent the law allows, and no broader than the contract requires. Payment is capped at the lesser of the contract's required limit or the policy limit.
The classic pitfall is treating the certificate of insurance as proof. A certificate only reports what is on the policy; the endorsement grants the status, so ask for a copy. Status also shares limits with the named insured and every other insured rather than adding new ones. The guide on additional insured endorsements covers the form editions and contract wording.
Last reviewed October 10, 2026