If your subcontract insurance clause mentions "additional insured" without naming specific forms, you are leaving compliance ambiguous. In US commercial construction, the standard pair is:
- CG 20 10 — Additional Insured for ongoing operations
- CG 20 37 — Additional Insured for completed operations
Missing either one creates a gap that may not show up until years after the sub leaves the jobsite.
CG 20 10: coverage while work is active
CG 20 10 extends the subcontractor's commercial general liability (CGL) policy to name upstream parties (GC, owner, etc.) as additional insureds for claims arising from the sub's ongoing operations.
"Ongoing operations" means work that is currently in progress — the period when the sub is physically on site or actively performing scope.
Example: A plumber's employee damages a finished wall during rough-in. CG 20 10 is the form that typically supports AI coverage for that type of claim.
CG 20 37: coverage after work is done
CG 20 37 extends additional insured status for completed operations — claims that arise after the subcontractor's work is finished.
This is critical for construction because:
- Structural defects may not manifest for months or years
- Water intrusion, electrical faults, and installation errors often surface after occupancy
- Statutes of repose can extend liability windows far beyond project closeout
Example: A tile installation fails six months after punch list, flooding a kitchen. Without CG 20 37, your AI protection from the sub's policy may have ended when they finished — even if the COI still looks fine on paper.
Why GCs require both
Most commercial subcontracts and owner-GC agreements require AI coverage for the full risk window of the project — not just the active construction phase.
Industry data consistently shows CG 20 37 is the most commonly missed endorsement in construction COI programs. Teams verify CG 20 10 at onboarding and assume "additional insured" covers everything.
It does not.
What to look for on the COI
In the ACORD 25 description of operations box, you might see language like:
Certificate holder is included as additional insured for ongoing and completed operations per CG 20 10 and CG 20 37.
That language is helpful — but you still need to confirm the endorsements exist on the policy. A checkbox or note on the certificate does not create AI status.
Verification steps
- Match endorsement edition dates to contract requirements (04 13 editions are current standard)
- Confirm your legal name appears on the endorsement schedule or blanket AI wording applies
- Store PDF copies of endorsements with the COI
- For high-stakes projects, call the sub's agent to confirm AI is in force
Other endorsements often bundled with AI
Subcontracts frequently stack requirements:
| Requirement | Typical form / mechanism |
|---|---|
| Primary & noncontributory | CG 20 01 or equivalent |
| Waiver of subrogation | CG 24 04 or state-specific |
| Per-project aggregate | CG 25 03 |
Each requires an endorsement — not a COI note.
Remodeling GC context
On a whole-home remodel, subs cycle in and out over 4–9 months. Plumbing and electrical completed ops exposure lasts far longer than the active schedule.
If you are the GC of record, owners and lenders increasingly ask for documentation that completed ops AI was in place for every trade — not just that you collected a COI at the start.
Checklist for your sub packet
- CG 20 10 referenced and confirmed on policy
- CG 20 37 referenced and confirmed on policy
- Your entity named correctly
- Limits meet contract ($1M/$2M minimum typical)
- Expiration covers project duration or renewal process defined
Tools vs manual review
Reading endorsement form numbers on every sub COI is tedious — but skipping it is how uninsured gaps survive audits.
CoiLoop lets GCs configure default insurance requirements (including AI checklist items) so review happens against your contract standard, not from memory.
FAQ
What is CG 2010?
CG 2010, often written as CG 20 10, is the ISO additional insured endorsement for ongoing operations. It applies while the subcontractor's work is active.
What is CG 2037?
CG 2037, often written as CG 20 37, is the additional insured endorsement for completed operations. It matters after the subcontractor finishes work.
Do you need both CG 20 10 and CG 20 37?
Most construction contracts require both because claims can arise during active work and after completion. A COI that references only one may leave a gap.
Related: Certificate holder vs additional insured · COI compliance checklist