CG 20 10 is the additional insured endorsement covering ongoing operations, meaning liability arising while the work is being performed. CG 20 37 covers products and completed operations, meaning liability arising after the work is finished. They are separate forms and a contract requiring additional insured status for both needs both attached.
Updated September 2026.
Why brokers care
This is the most consequential detail in certificate work and the one most often missed. A certificate says additional insured, the CG 20 10 is attached, and the requirement looks satisfied. Years later a defect in completed work produces a claim, the endorsement does not reach it, and the client discovers the gap at the worst possible moment. The two forms cost very little to arrange together and a great deal to discover separately.
What to check
- Which form is actually attached, by number, not by the certificate wording
- Whether the contract requires completed operations, explicitly or by implication
- The edition date of the form, since coverage has narrowed across editions
- Whether a blanket endorsement is being relied on instead, and what it reaches
- How long completed operations status must be maintained after the work ends
Common mistake
Checking that an additional insured endorsement exists without checking which one. Both satisfy a quick look at the certificate. Only one of them responds after the work is finished.
This is the error pattern set out in the E&O exposure guide.