Additional Insured Endorsement: What It Is and What to Check

What an additional insured endorsement adds to your GL policy

An additional insured endorsement amends your general liability policy's "who is an insured" section. It adds another party — usually a GC, property owner, landlord, or public agency — as an insured for a defined relationship or set of circumstances.

The added party does not own your policy, control your limits, or receive unrestricted coverage. They receive only the protection the endorsement wording grants, limited to the relationship described.

AIG describes it as an amendment to one party's insurance policy that adds another party as an insured under that policy. The endorsement gives the additional insured direct access to your GL policy for covered claims tied to your work. That means the GC or owner can look to your policy for defense of a potentially covered claim without filing against their own coverage first.

Additional insured vs named insured vs certificate holder

Contractors often confuse three statuses that appear on certificates and policies. Each one means something different for coverage.

• Named insured: owns the policy, pays the premium, controls cancellation and changes.
• Additional insured: receives defined coverage under someone else's policy through an endorsement. Does not pay premium or control the policy.
• Certificate holder: receives evidence that a policy exists. Certificate-holder status alone does not create policy rights.

Many contractors see a certificate of insurance request first and never see the endorsement form. The certificate shows evidence. The endorsement controls what the policy actually covers.

Ongoing operations vs completed operations: CG 20 10 and CG 20 37

The most common contract confusion for contractors is which endorsement form covers which time period. CG 20 10 covers liability while your work is in progress. CG 20 37 covers liability after the work is completed.

Construction contracts usually require both forms. A GC or owner can be sued while you are on the job and months or years after you finish. If your policy only has CG 20 10, the additional insured has no coverage for claims that arise after completion.

Why the date of injury matters, not the date of work

For completed operations claims, the important date is when injury or damage occurs — not when the faulty work was performed. If an electrical contractor rewired a building in 2024 and a fire caused by the wiring occurs in 2025, the additional insured needs completed-operations coverage on the contractor's 2025 policy.

ISO introduced CG 20 37 in 2001 to restore completed operations coverage for additional insureds after that coverage had been removed from CG 20 10. Before 2001, CG 20 10 covered both time periods. After 2001, you need both forms to cover both periods.

Not every contract requires both forms. A short service visit, a lease, or a one-day event permit may only need ongoing operations coverage. Compare the contract language against the actual job before requesting both.

How endorsement wording affects what the policy actually covers

The edition date on your endorsement changes how broadly the policy covers the additional insured. Two wording differences matter most.

'Arising out of' vs 'caused by acts or omissions'

Before 2004, the widely used CG 20 10 11 85 edition triggered coverage for losses "arising out of" the named insured's work. Starting with the 07 04 edition, ISO changed the trigger to "caused by acts or omissions" of the named insured.

"Arising out of" is generally less restrictive than "caused by acts or omissions." Under the older wording, a loss only needed a connection to the named insured's work. Under the newer wording, the named insured's acts or omissions must have caused the loss. That is a narrower trigger.

Some contracts still request CG 20 10 11 85 because of the broader trigger language. That edition is generally not available from carriers today. If your contract asks for it, ask the contract owner whether a current edition with equivalent language is acceptable.

The 2013 contract-cap rule

The 2013 ISO additional insured endorsements added a rule: if coverage for the additional insured is required by contract, the insurance afforded will not be broader than what the contract requires.

This means the contract language now limits the endorsement scope. A broad endorsement paired with a narrow contract requirement may not produce broad coverage. The endorsement and the contract work together — neither one alone controls the result.

AIG states that additional insured coverage is determined by the endorsement language, not by the contract language. Indemnification and additional insured coverage are separate risk-transfer mechanisms. The contract may promise indemnity, but the endorsement controls what the policy pays.

Primary and noncontributory wording and waiver of subrogation

Contracts often list three requirements in one sentence: additional insured, primary and noncontributory, waiver of subrogation. Each one is a separate endorsement or policy provision. Additional insured status alone does not provide the other two.

What primary and noncontributory means

Primary means your policy pays before the additional insured's own policy or self-insurance. Noncontributory means your policy does not seek contribution from the additional insured's policy, even if both policies are triggered by the same loss.

Without primary and noncontributory wording, both policies might share defense costs and damages as contributing primary policies. The contract owner wants to avoid that outcome.

AIG advises parties receiving additional insured coverage to require primary language. If the endorsement does not include it, the additional insured's own policy may still be called on to contribute.

Waiver of subrogation: why contracts ask for it alongside AI status

A waiver of subrogation is the carrier's acknowledgment that it will not recover against a liable third party after paying a loss on behalf of its insured.

Contracts may need both additional insured status and a waiver of subrogation because some losses fall outside the scope of the additional insured endorsement, exceed agreed limits, or involve policies that do not offer additional insured status — like workers compensation or professional liability. The waiver prevents the carrier from recovering against the additional insured for those losses.

One more gap: being added as an additional insured on a primary policy does not mean the party is also added to excess or umbrella layers. If the contract requires umbrella coverage for the additional insured, confirm that the umbrella policy includes the same endorsement.

Blanket vs scheduled endorsements: which one your policy uses

There are two ways carriers add additional insureds to a policy: scheduled endorsements and blanket endorsements. The difference affects how quickly you can issue certificates and what documentation you need.

Scheduled endorsements

A scheduled endorsement names the additional insured party, the project or location, and the relationship. Each time a new contract requires additional insured status, you ask your carrier to add a new schedule entry. This takes time and may involve a fee for each addition.

Blanket endorsements

A blanket (or automatic) endorsement grants additional insured status to any party when a written contract requires it. The key requirement: the named insured must have agreed in writing to add the party.

"Blanket" does not mean every client is automatically covered. If there is no signed contract that requires additional insured status, the blanket endorsement may not respond. A verbal agreement or a handshake deal is not enough to trigger the wording.

Confirm with your carrier before relying on blanket wording

AIG advises policyholders to confirm the cost and availability of required additional insured coverage with the insurance company before agreeing to provide it. If your policy uses blanket wording, confirm that the written contract you are signing meets the endorsement's trigger requirements. If your policy uses scheduled wording, confirm turnaround time for adding a new party.

How to check your policy against a contract requirement

Before you sign a contract or send a certificate, compare these items on your policy against the contract's insurance requirements. Missing any one can result in a rejected certificate or a coverage gap at claim time.

Some contract owners require more than a certificate. Caltrans, for example, requires the successful bidder to submit a copy of the CGL policy and excess policy or binder, including declarations, applicable endorsements, riders, and modifications. If your contract requires actual policy documents, make sure you can produce them — not just an ACORD certificate.

Many contract owners accept equivalent forms. Sonoma County, for example, references ISO endorsements but accepts other endorsements with equivalent or similar language. However, proprietary completed-operations endorsements that restrict coverage to work done during the current policy period are often rejected because completed-operations claims can arise months or years after the work is finished.

Check which endorsement forms your contract requires

Answer a few questions about your contract's insurance language. The tool shows which endorsement forms your GL policy needs to provide.

Send a clear endorsement request to your carrier

Once you know which forms your contract requires, use this checklist to request the correct endorsement from your carrier or agent. A structured request prevents back-and-forth and missed details.

What the endorsement costs and how to confirm availability

There is no universal price for an additional insured endorsement. The cost depends on your carrier's rules and what the contract requires.

The endorsement does not add new policy limits. Named insureds and additional insureds share the same per-occurrence and aggregate limits. If you have many contracts requiring additional insured status under the same annual limit, two large claims from different additional insureds can exhaust the aggregate.

Confirm cost and availability with your carrier before signing the contract. If your carrier cannot provide the required form, primary wording, completed operations coverage, or waiver of subrogation, you may not be able to satisfy the contract's insurance requirements after you have already committed.

The marketplace compares your account with carriers from 400+ carrier and market options that insure your kind of work. Licensed support in 22 states can help you confirm whether a carrier's GL policy includes the endorsement wording your contract requires.

Compare GL policies that include the endorsement your contract requires

The right GL policy for your work includes the endorsement forms, primary wording, completed operations coverage, and waiver of subrogation your contracts require. Not every carrier offers every form or edition.

Submit one quick form. The marketplace compares your account with carriers that insure your kind of work and can provide the endorsement wording your contract requires. Licensed insurance professionals can review the options with you.

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