# Additional insured: CG 20 10 vs CG 20 37

> Learn what additional insured status means, how CG 20 10 (ongoing work) differs from CG 20 37 (completed work), and how to verify the real endorsement.

An additional insured is a party added to someone else's liability policy so it has its own coverage under that policy. In construction, ISO form CG 20 10 gives additional insured status for ongoing operations, and CG 20 37 gives it for completed operations, meaning claims that arise after the work is finished. A general contractor or owner usually wants both, because a claim can show up years after the job.

## What additional insured status gives you

When a subcontractor adds you as an additional insured, you can be covered for liability arising from the subcontractor's work, under the subcontractor's general liability policy. That is different from being a certificate holder, who only receives a copy of the certificate. See [certificate holder vs additional insured](https://complysub.agntwrk.com/guides/certificate-holder-vs-additional-insured).

The scope depends on the endorsement wording. It is not automatic, and it is not unlimited.

## CG 20 10: ongoing operations

CG 20 10 is the ISO endorsement titled Additional Insured, Owners, Lessees or Contractors, Scheduled Person or Organization. It covers the added party for liability caused by the named insured's ongoing work for that party. The coverage generally stops when the work is completed. It names each additional insured on a schedule.

## CG 20 37: completed operations

CG 20 37 is the companion endorsement for completed operations. It covers the added party for liability arising from the named insured's work after that work is finished and put to its intended use. Defect and damage claims on finished projects often surface late, which is why many contracts require both forms.

| Question | CG 20 10 | CG 20 37 |
| --- | --- | --- |
| When does it apply? | While the work is ongoing | After the work is completed |
| Typical concern | Injury or damage during construction | Claims that arise after turnover |
| Usually required by | Nearly every GC and owner | Most GCs and owners on construction work |

## Blanket and scheduled wording

Many carriers offer blanket additional insured endorsements that add any party the policy holder agreed to cover in a written contract. ISO has forms of this type, commonly numbered CG 20 33 and CG 20 38, and many carriers have their own proprietary versions. Their wording differs, so do not assume two blanket endorsements give the same protection. Some blanket forms cover ongoing operations only, some cover completed operations as well, and some carrier forms require that the contract be signed before the loss.

A scheduled endorsement lists you by name. A blanket endorsement does not, so the certificate may not show your name anywhere except in the description of operations.

## Edition dates matter

ISO revises these forms. The edition date, printed at the bottom of the endorsement, can change what is covered. Later editions, for example, tie coverage to what the written contract requires and to the extent the law allows. Some contracts name a minimum edition, or ask for the endorsement to be no more restrictive than an earlier one. If your contract specifies editions, ask the agent for the endorsement forms and check the edition on each. If it does not, ask your own attorney or insurance professional whether it should.

## How to check the real endorsement

The Y in the ADDL INSD column of the ACORD 25 is a statement by the agent. It does not prove the endorsement exists or covers you. To verify:

1. Ask the vendor's agent for a copy of the additional insured endorsements, with the form numbers and edition dates.
2. Confirm the policy number on the endorsement matches the one on the certificate.
3. Check that it applies to your entity name, either by schedule or by blanket wording that fits your contract.
4. Check that both ongoing and completed operations are covered if your contract requires both.
5. Note the expiration, and ask for the new endorsement at each renewal.

Coverage disputes turn on policy wording and state law. For contract language, talk with an insurance professional or an attorney. See also [how to write subcontract insurance requirements](https://complysub.agntwrk.com/guides/writing-subcontract-insurance-requirements) and [how to read an ACORD 25](https://complysub.agntwrk.com/guides/acord-25-certificate-field-by-field).

## Check this automatically

In ComplySub you set the additional insured requirement once, for example ongoing and completed operations, and your exact entity name. Vendors upload their certificate through a link, with no account. ComplySub flags certificates that do not show additional insured status or the required wording, and reminds the vendor and their agent to correct it. It reads the certificate. It cannot see the policy endorsement itself, so ask for the endorsement on important jobs. ComplySub is not legal or insurance advice.

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_This guide is general information, not legal or insurance advice. Insurance and licensing rules vary by state, carrier, and contract; confirm what applies to you with your insurance professional, attorney, or licensing board._