When a general contractor asks a subcontractor to provide additional insured coverage, the phrase “additional insured” can hide an important question: Does the requirement cover only ongoing operations, or does it also address completed operations?
Two ISO endorsement forms that frequently appear in construction insurance discussions are CG 20 10 and CG 20 37. They address different stages of the subcontractor's work, so a compliance process should not treat them as interchangeable.
This guide explains the distinction in practical terms, what a general contractor should check, and how to turn the requirement into a trackable compliance item. Form editions and exact wording can vary, so the contract and actual endorsement should always be reviewed for the project in question.
The short answer
At a high level:
- CG 20 10 is associated with additional insured coverage for liability arising from the named insured's ongoing operations.
- CG 20 37 is associated with additional insured coverage for liability arising from the named insured's completed operations.
The two concepts address different points in the project lifecycle. A contract that requires additional insured protection for both ongoing and completed operations may therefore require both types of endorsement support.
Do not assume that a generic reference to “additional insured” automatically tells you which forms or coverage periods are required. The contract language and endorsement wording control.
What is an additional insured endorsement?
An additional insured endorsement modifies an insurance policy to provide specified coverage to a party other than the named insured, subject to the endorsement's terms, conditions, limitations, and the underlying policy.
For a general contractor, the subcontractor's policy may be required to provide additional insured status to the GC or another upstream party for liability connected with the subcontractor's work.
The important distinction is that being listed as a certificate holder is not the same thing as being an additional insured. A certificate can communicate information about a policy, but the actual rights come from the policy and applicable endorsements.
What does CG 20 10 address?
CG 20 10 is an additional insured endorsement associated with ongoing operations.
In practical construction terms, think about work that is still being performed. A subcontractor's crew is installing equipment, framing a structure, pouring concrete, or performing another contracted scope.
If the contract requires additional insured protection for ongoing operations, the relevant endorsement needs to provide the required protection for that work and within its stated terms.
Example
A plumbing subcontractor is actively installing piping. During construction, an incident occurs that leads to a claim connected with the subcontractor's ongoing work.
If the subcontractor's policy contains an applicable additional insured endorsement for ongoing operations that covers the required party and circumstances, that endorsement is the part of the insurance program that needs to be reviewed—not merely the certificate holder field on the COI.
What does CG 20 37 address?
CG 20 37 is associated with additional insured coverage for completed operations.
This matters because some construction claims do not appear while a subcontractor is actively working. A defect, failure, or resulting injury may become apparent after the subcontractor has finished its scope and left the project.
Example
A subcontractor completes roofing work and the project is occupied. Months later, a problem connected with the completed work results in property damage or another claim.
If the contract requires completed-operations additional insured protection, the relevant endorsement and policy terms need to support that requirement.
The exact scope of coverage depends on the endorsement wording and policy. This article does not treat the form number alone as a guarantee of coverage.
CG 20 10 vs. CG 20 37 at a glance
| Issue | CG 20 10 | CG 20 37 |
|---|---|---|
| Primary concept | Ongoing operations | Completed operations |
| Lifecycle | Work being performed | Work after completion |
| Why a GC may request it | Protect required upstream party during active work | Address post-completion exposure when required |
| Should it be treated as interchangeable with the other? | No | No |
| What should be reviewed? | Actual endorsement and policy terms | Actual endorsement and policy terms |
The table is a practical summary, not a substitute for reading the applicable form.
Why completed operations matters to general contractors
A construction project does not necessarily eliminate risk when the subcontractor's crew leaves the site.
A roof can leak after completion. A mechanical installation can fail after turnover. A waterproofing problem can become visible months later. A defect can create a claim after the original work has been completed.
The contract may therefore require risk-transfer provisions that address both the active construction period and the post-completion period.
That is why a compliance reviewer should ask a more precise question than “Is additional insured coverage included?”
Ask:
What additional insured protection does the contract require, and does the endorsement we received support that requirement for the required period and operations?
What should a GC request from a subcontractor?
Start with the contract.
If the contract specifies particular endorsement forms, wording, editions, or completed-operations requirements, request the documents that establish those requirements.
A practical file may include:
- Current COI
- Applicable additional insured endorsement(s)
- Insurance requirements exhibit
- Contract/subcontract
- Policy information where the contract or review requires it
- Review notes
- Approval status
The goal is to connect the requirement to the evidence rather than simply collect PDFs.
Does an ACORD 25 prove CG 20 10 or CG 20 37 exists?
Not by itself.
The ACORD 25 is a certificate used to summarize insurance information. It is not the insurance policy and does not replace the underlying endorsement.
A certificate may reference additional insured status, but when the contract requires an endorsement, the endorsement itself should be part of the compliance file and reviewed according to the applicable requirement.
This distinction is important because a checkbox or description on a certificate cannot rewrite the underlying policy.
What should you look for when reviewing an endorsement?
The exact review depends on the contract and the form, but a GC can structure the process around several questions:
- Is the correct subcontractor named as the insured?
- Is the correct GC/owner/entity identified as the additional insured where required?
- Does the endorsement address ongoing operations, completed operations, or both as required?
- Does the endorsement apply to the relevant project, location, or operations?
- Is the endorsement consistent with the contract's wording and requirements?
- Are there restrictions or limitations that require escalation to an insurance professional?
- Is the applicable policy period current?
- Has the review been documented?
A compliance team should not make a legal coverage determination merely from the endorsement title. Escalate interpretation questions to the broker, carrier, attorney, or other qualified professional as appropriate.
Common mistake: accepting “additional insured” without checking the scope
One of the easiest mistakes is to make the compliance field binary:
Additional insured: Yes
That may be too vague for a complex construction requirement.
A better record could separate:
| Requirement | Status |
|---|---|
| Additional insured — ongoing operations | Reviewed |
| Additional insured — completed operations | Pending |
| Primary/noncontributory | Reviewed separately |
| Waiver of subrogation | Reviewed separately |
This makes it much harder for a broad “AI approved” label to hide a missing requirement.
What does “20/37” mean?
Construction insurance professionals sometimes use “20/37” as shorthand for a combination of CG 20 10 and CG 20 37 requirements.
When a subcontract says that additional insured status must be provided on a “20/37” basis, the practical question is whether the subcontractor's insurance documentation contains the required ongoing- and completed-operations endorsements in the form and edition required by the contract.
Do not assume that the shorthand itself is a universal legal standard. The actual contract and endorsement wording should be reviewed.
CG 20 10 and CG 20 37 are not the same as primary and noncontributory
These requirements are often listed together, but they perform different functions.
- Additional insured endorsement: addresses who receives specified additional insured protection and under what terms.
- Primary and noncontributory requirement: addresses the intended order or contribution relationship between insurance policies when the contract requires it.
- Waiver of subrogation: addresses certain insurer recovery rights against a protected party.
A compliance workflow should track them separately instead of assuming one endorsement satisfies all three.
A practical additional insured review workflow
Step 1: Read the contract
Identify exactly what additional insured status is required, for whom, for which coverage, and for what period.
Step 2: Collect the COI
Use the certificate to identify the policy and confirm the basic insurance information.
Step 3: Collect required endorsements
Request the actual endorsement documents when the contract requires them.
Step 4: Compare the evidence
Check the endorsement against the contracting entity, required party, project/location, operations, and timing requirements.
Step 5: Record exceptions
If the endorsement is missing or does not obviously match the requirement, mark the item pending or for professional review instead of assuming compliance.
Step 6: Monitor renewal
When the policy renews, request and review the updated evidence again if the requirement continues.
How to track CG 20 10 and CG 20 37 in a compliance system
Instead of one field called “Additional Insured,” create requirement-level records such as:
| Compliance item | Evidence | Status | Renewal |
|---|---|---|---|
| AI — ongoing operations | CG 20 10 endorsement | Approved/Pending | Policy expiration |
| AI — completed operations | CG 20 37 endorsement | Approved/Pending | Policy expiration |
| Primary/noncontributory | Required endorsement/language | Approved/Pending | Policy expiration |
| Waiver of subrogation | Required endorsement | Approved/Pending | Policy expiration |
This structure helps a project manager see exactly what is missing without opening every PDF.
What happens when the endorsement is missing?
Do not silently mark the subcontractor compliant.
A useful exception might say:
Pending — contract requires additional insured protection for completed operations; current COI received, required endorsement not yet verified.
Then assign the next action and due date according to your internal process.
Frequently asked questions
What is the difference between CG 20 10 and CG 20 37?
CG 20 10 is associated with additional insured coverage for ongoing operations, while CG 20 37 is associated with completed operations. They should not be treated as interchangeable.
Does every subcontractor need both endorsements?
Not automatically. The required endorsements depend on the contract, project, insurance program, and applicable policy terms.
Is CG 20 10 enough for a completed-operations requirement?
Do not assume so. If the contract requires completed-operations additional insured protection, verify the actual endorsement and policy language that satisfies that requirement.
Is being listed as a certificate holder the same as being an additional insured?
No. Certificate holder status and additional insured status are different concepts.
Can a COI replace the endorsement?
No. When the contract requires an endorsement, the underlying endorsement should be obtained and reviewed rather than relying only on certificate wording.
Should primary and noncontributory be tracked separately?
Yes. It is a separate contractual insurance requirement and should be reviewed separately from additional insured status.
Final takeaway
CG 20 10 and CG 20 37 address different parts of the construction lifecycle. CG 20 10 is associated with ongoing operations, while CG 20 37 addresses completed operations. For general contractors, the practical lesson is to stop treating “additional insured” as a single checkbox.
Build the compliance requirement from the contract, collect the evidence required to support it, review the actual endorsement, document exceptions, and monitor the requirement through renewal.
SubCada can help contractors organize insurance requirements, supporting documents, expiration dates, and compliance status so your team can see which requirements are complete and which still need attention.
This article is general informational content and is not legal or insurance advice. Insurance forms and requirements vary by carrier, contract, jurisdiction, and project. Consult your broker, carrier, or construction counsel for project-specific interpretation.
