🎯 CG 20 10 covers your general contractor during ongoing operations; CG 20 37 covers them for completed operations after you finish the job. Most GC subcontract exhibits require BOTH, because the 2013 edition of CG 20 10 (form CG 20 10 04 13) stripped out the completed-operations coverage that older editions implied. If your certificate shows only CG 20 10 and the contract names both, your COI gets rejected. The fix: ask your agent to add the completed operations endorsement CG 20 37 and reissue.
Last updated: October 2026.
TL;DR
- CG 20 10 = additional insured for ongoing operations (while you're on site working).
- CG 20 37 = additional insured for completed operations (after your work is done and signed off).
- Many commercial GC subcontracts ask for both forms by number. One without the other is a rejection waiting to happen.
- Whether adding the endorsements changes your premium is set by your insurer; ask your agent before you bid, not after you win the job.
- Request both endorsements before you submit your final bid, not after you win. Retroactive endorsements are harder to place and sometimes refused.
Methodology: This is a fit-first form-selection guide. We match endorsement forms to contract language and the governing ISO edition — we do not rank carriers, sell policies, or recommend forms based on any reward or commission. The "right" endorsement is the one your signed subcontract actually requires by form number. Form wording and edition references are drawn from current ISO standard forms and the carrier/risk-management sources cited throughout, each with an access date.
What is the difference between CG 20 10 and CG 20 37?
CG 20 10 and CG 20 37 are both ISO additional insured endorsements, but they cover two different windows of time.
CG 20 10 adds your GC as an additional insured on your general liability policy during ongoing operations — the period while your crew is actively performing the work. CG 20 37 adds your GC as an additional insured for completed operations — claims that arise from your finished work after you've left the site. "Additional insured" means the GC gets protection under your policy; a certificate of insurance (COI) only reports that coverage exists, it does not create it. The endorsement is the thing that actually matters.
The GC wants both because construction claims split neatly across that timeline. A trench collapse while you're digging is an ongoing-operations claim (CG 20 10). A roof that leaks and rots framing eighteen months after you finish is a completed-operations claim (CG 20 37). Name only one endorsement and you've left the GC exposed on the other half of the job.
The International Risk Management Institute (IRMI) describes this same ongoing-vs-completed split and warns that relying on a single endorsement commonly leaves a coverage gap. See IRMI, "Additional Insured Issues in Construction" (accessed October 14, 2026): https://www.irmi.com/term/insurance-definitions/additional-insured.
Why does my GC need both endorsements, not just CG 20 10?
Because the 2013 edition of CG 20 10 deliberately removed completed-operations coverage.
Older editions (like CG 20 10 10 01) were sometimes read to extend coverage into the completed-operations period. ISO closed that gap. The current CG 20 10 04 13 wording limits the additional insured to "ongoing operations performed for that additional insured." Read it literally and the GC loses protection the day you demobilize. ISO's additional insured endorsement library — including the 04 13 and later maintained editions of CG 20 10 and CG 20 37 — is published through Verisk/ISO's commercial general liability program (accessed October 14, 2026): https://www.verisk.com/insurance/products/iso-forms/.
That single edition change is why modern insurance-requirements exhibits list both forms by number. The GC's risk manager knows CG 20 10 04 13 no longer carries completed ops, so they bolt on the completed operations endorsement CG 20 37 to get it back.
What happens when a contract names both forms?
When a contract says "additional insured status for ongoing AND completed operations per ISO forms CG 20 10 and CG 20 37 (or equivalent)," it is telling you three things at once:
- Both endorsements must be on the policy — not just referenced on the certificate. The COI is a summary; the endorsement pages are the proof. Ask your agent for copies of the actual endorsement forms, not only the certificate.
- The edition dates matter. Because CG 20 10 04 13 dropped completed ops, a GC who requires both forms is doing so precisely to close that gap. Confirm your CG 20 10 edition and that CG 20 37 is attached and current.
- "Or equivalent" is not a blank check. Some carriers use proprietary blanket additional insured endorsements instead of the ISO numbered forms. These may satisfy the contract — but only if the wording grants both ongoing and completed operations status. Have your agent confirm equivalence in writing before you certify compliance.
A note on price
This guide gives no price. Whether either endorsement carries a charge, and how much, is set by your insurer for your class of business, limits and policy. Ask your own agent for the exact charge in writing.
Before you issue the COI — don't certify yet
Do not have your agent issue a certificate claiming both endorsements until you have seen the actual endorsement forms attached to the bound policy. Issuing a COI that overstates coverage can expose you to liability if a claim later reveals the completed-operations endorsement was never on the policy. The safe sequence is: read the subcontract exhibit → request both endorsements from your agent → verify the forms and edition dates → then issue the certificate.
FAQ
Does CG 20 10 04 13 include completed operations? No. The 2013 edition (CG 20 10 04 13) limits additional insured status to "ongoing operations performed for that additional insured." Completed operations must be added separately with CG 20 37.
Can I use CG 20 37 alone? Only if the contract asks for completed operations alone, which is rare. CG 20 37 covers the post-completion period; it does not cover you while work is in progress. Most contracts require CG 20 10 and CG 20 37 together.
Is a certificate of insurance enough to prove I have both? No. A COI reports coverage; the endorsement forms create it. Request copies of the attached CG 20 10 and CG 20 37 endorsements and confirm their edition dates.
When should I request these endorsements? Before submitting your final bid. Adding or correcting endorsements after award can delay your start and is occasionally refused by the carrier.