CG 20 10 and CG 20 37: Do You Need Both? (CG2010 / CG2037)

Last updated July 2026.

CG 20 10 and CG 20 37 are the two ISO additional insured endorsement forms construction contracts ask for most. CG 20 10 grants additional insured status for the vendor's ongoing operations, the work while it is being performed. CG 20 37 grants it for completed operations, the finished work after the crew leaves. They cover different phases of the same project, which is why well written contracts require both.

If you review certificates of insurance for a general contractor, a developer or a property owner, these two form numbers (you will also see them written CG2010 and CG2037, with no spaces) show up in the description of operations box constantly, and the difference between them decides whether you are actually protected after a project closes out. Here is what each one does, when you need both, and how to confirm they are real rather than typed onto a certificate.

Both forms exist inside a larger family. ISO publishes a separate additional insured endorsement for almost every relationship, from landlords to ground lessors to equipment vendors, and the one your contract needs depends on which of those you are. The full set is listed in the additional insured endorsement forms reference. The edition date printed after each form number also changes what it grants, which is worked through in CG 20 10 edition dates.

What is the difference between CG 20 10 and CG 20 37?

CG 20 10 adds you as an additional insured for the named vendor's ongoing operations, meaning liability arising while the work is still underway. CG 20 37 adds you for completed operations, meaning liability that surfaces after the work is finished and handed over. A slip during framing is ongoing operations. A framing defect that causes a collapse two years later is completed operations. One form does not cover the other, so many injuries and property claims fall into a gap if only one is attached.

What is CG 20 10?

CG 20 10 is the ISO endorsement titled Additional Insured, Owners, Lessees or Contractors, Scheduled Person or Organization. It extends the named insured's general liability coverage to the person or organization listed, for liability caused in whole or in part by the named insured's ongoing operations. On a subcontractor's policy, it is what makes the general contractor and the owner additional insureds while the subcontractor is on site working.

What is CG 20 37?

CG 20 37 is the companion endorsement, Additional Insured, Owners, Lessees or Contractors, Completed Operations. It extends the same additional insured status to liability arising out of the work after it is put to its intended use. Construction defects rarely appear during the job. They appear months or years later, which is exactly the window CG 20 37 covers and CG 20 10 does not.

Do I need both CG 20 10 and CG 20 37?

Yes, on construction work you almost always need both. CG 20 10 protects you during the project and CG 20 37 protects you after it, and construction claims routinely arrive years after completion when only the completed operations form responds. A contract that requires additional insured status for ongoing and completed operations, or names both form numbers, is asking for the pair. Requiring only CG 20 10 leaves the long tail of defect claims uncovered.

What does a contract mean by "CG 20 10 and CG 20 37 or equivalent"?

It is asking for two separate grants of additional insured status, one for work in progress and one for work already finished, and it is allowing the vendor's carrier to deliver them on non-ISO forms that do the same job. Many carriers use their own combined or blanket versions rather than attaching the two ISO forms by number.

The word equivalent is where these clauses get tested. A carrier form is only equivalent if it actually reaches completed operations, and a good number of blanket additional insured endorsements stop at ongoing operations exactly the way CG 20 10 does. So when a certificate comes back with an unfamiliar form number instead of the pair, the question to ask is not whether the number matches but whether the wording extends to the products-completed operations hazard. If it does not, the vendor has met the letter of the clause and missed the point of it.

What the CG 20 10 12 19 form actually says

Transcribed from an issued endorsement filed with a municipal contract, the current edition amends Section II Who Is An Insured to add the scheduled person or organization as an additional insured for bodily injury, property damage or personal and advertising injury caused, in whole or in part, by the named insured's acts or omissions, or those of anyone acting on their behalf, in the performance of the named insured's ongoing operations at the scheduled location.

Two limitations then follow in the same paragraph. The insurance applies only to the extent permitted by law, and where coverage is required by a contract, it will not be broader than what the contract required the named insured to provide. A separate paragraph excludes damage occurring after all work at the location is complete or after the work has been put to its intended use. That exclusion is the completed operations gap in plain sight, and it is the reason CG 20 37 has to be attached alongside rather than assumed.

What does the CG 20 10 04 13 edition change?

The 04 13 edition of CG 20 10 narrows coverage in two ways worth catching. It limits additional insured coverage to the extent permitted by law and to the coverage required by the contract, and it explicitly excludes completed operations. That completed operations exclusion is the main reason CG 20 37 has to be attached separately. If a subcontractor gives you only a 04 13 edition CG 20 10 and no CG 20 37, your completed operations protection is missing even though a form number is present.

Is CG 20 10 blanket or scheduled?

The standard CG 20 10 is a scheduled form, meaning it names the specific additional insured in a schedule on the endorsement. Blanket additional insured coverage is provided by different forms or by policy wording that grants status to anyone the named insured has agreed in a written contract to add, such as CG 20 33 or CG 20 38 for ongoing operations. Blanket wording is convenient, but you still need to confirm it actually reaches completed operations, since many blanket forms cover only ongoing work. The blanket versus scheduled distinction is separate from the ongoing versus completed operations distinction, and both matter.

How do I verify CG 20 10 and CG 20 37 on a certificate of insurance?

The certificate itself is not proof. The description of operations box on an ACORD 25 may say additional insured per CG 20 10 and CG 20 37, but that text is typed by whoever issued the certificate and is not the policy. To verify, request copies of the actual endorsements and confirm the form numbers, the edition dates, the named insured and that you or your entity are covered, whether by schedule or by qualifying blanket language. If you are digitizing a backlog of paper endorsements to check them at scale, you can pull the key fields out of each document automatically rather than reading every page by hand. For a walkthrough of the rest of the form, see how to read a certificate of insurance.

Track the endorsements, not just the certificate

Most COI programs fail not because they miss the certificate but because they never confirm the endorsements behind it. Requiring CG 20 10 and CG 20 37 in your contracts is step one. The same discipline applies to the per project aggregate endorsement, which keeps one job claim from eroding the limit protecting yours. Confirming both endorsements are actually attached, current and correct on every renewal is the ongoing work, and it is what separates a real compliance program from a folder of PDFs. That is the job COI tracking for general contractors is built for: it reads each ACORD 25, checks your required coverages and endorsement wording automatically, and flags a subcontractor whose completed operations coverage is missing before they set foot on site. Teams running compliance through Procore can do the same with COI tracking for Procore, since the platform stores the endorsement note but does not verify it, as we cover in tracking certificates of insurance in Procore.

If you have to check these two forms across a real vendor list rather than settle the question once, our CG 20 10 and CG 20 37 endorsement verification page sets out the four checks that matter on an endorsement page and how they are automated. The edition date printed after CG 20 37 changes what that half of the pair grants, and each revision is transcribed from the ISO forms in CG 20 37 edition dates. For the wider context, completed operations coverage has its own guide in what is completed operations coverage, and the difference between being an additional insured and a certificate holder is covered in additional insured vs certificate holder. For the full list of forms that appear alongside these two on a certificate, see our reference table of certificate of insurance endorsements.