Additional Insureds
Status comes from an endorsement, not a certificate
An additional insured (AI) gains rights only through an endorsement attached to the named insured's policy. A certificate of insurance is evidence of coverage, not coverage itself, and creates no rights. Watch for certificates that say "additional insured" with no endorsement behind them, and endorsements that require a written contract executed before the loss.
Know the ISO forms
CG 20 10 - owners, lessees, or contractors, scheduled person or organization (ongoing operations). CG 20 11 - managers or lessors of premises. CG 20 33 - automatic AI status for owners, lessees, or contractors when required by a written construction agreement. CG 20 37 - completed operations. Standard AI wording covers the AI only for liability arising out of the named insured's operations, and usually only to the extent the named insured is liable. The AI's own independent negligence is often outside the grant.
Primary and noncontributory; waiver of subrogation
These are separate endorsements, not automatic. "Primary and noncontributory" changes the order in which policies respond; a waiver of subrogation stops the insurer from pursuing the AI after paying a loss. The insured-contract definition can also make a hold-harmless obligation covered, but only if the contract qualifies.
Traps to expect
AI status does not extend the AI's own products or completed operations unless a completed-operations endorsement is attached; adding an AI does not raise limits; blanket endorsements may require the contract be executed before the loss; and severability of interests treats each insured separately.
Worked example. A general contractor requires its electrical subcontractor to name it as AI for ongoing and completed operations, primary and noncontributory. The sub's policy carries only CG 20 10. After the project is finished, a tenant is injured by faulty wiring. The GC has no completed-operations coverage - a gap the certificate never revealed.