CG 20 10 and CG 20 37 Additional Insured Endorsements

ISO forms CG 20 10 and CG 20 37 are the standard Commercial General Liability endorsements that grant Additional Insured coverage to property owners and general contractors. CG 20 10 covers claims arising during active work (ongoing operations), while CG 20 37 covers claims after the job is finished (completed operations).

You can check an ACORD 25 certificate for free to detect both endorsement codes automatically.

Why You Need Both CG 20 10 and CG 20 37

Many contractors submit an ACORD 25 with CG 20 10 (or a blanket equivalent) but omit CG 20 37. Understanding the boundary between ongoing and completed operations shows why that leaves a critical coverage gap:

• Ongoing Operations (CG 20 10): Suppose Apex Plumbing LLC is soldering copper pipe on the third floor of a building owned by 123 Main Street Holdings LLC. A spark triggers water damage during the workday. Because Apex Plumbing LLC is actively performing the work, CG 20 10 responds.
• Completed Operations (CG 20 37): Suppose Apex Plumbing LLC finishes the repiping project in March, passes inspection, and demobilizes. In August, a faulty solder joint bursts overnight and floods three tenant suites. Because the work was already finished, CG 20 10 no longer applies—only CG 20 37 (under the Products-Completed Operations Hazard) extends Additional Insured status to 123 Main Street Holdings LLC and Harborview Property Management Inc..

Comparing Key ISO Additional Insured Endorsements

Developed by the Insurance Services Office (ISO / Verisk), Commercial General Liability endorsements use standardized form numbers and edition dates (such as 04 13 for April 2013 or 12 19 for December 2019).

ISO Form Number	Official Form Title	Operations Scope	How Entities Are Scheduled
CG 20 10 04 13	Additional Insured – Owners, Lessees or Contractors – Scheduled Person or Organization	Ongoing operations only	Lists specific entity names and project locations in the endorsement schedule (or states "As Required by Written Contract").
CG 20 37 04 13	Additional Insured – Owners, Lessees or Contractors – Completed Operations	Completed operations only (Products-Completed Operations Hazard)	Lists specific entity names and locations in the schedule. Must be paired with CG 20 10 for full lifecycle coverage.
CG 20 33 04 13	Additional Insured – Owners, Lessees or Contractors – Automatic Status When Required in Construction Agreement	Ongoing operations only	Blanket automatic coverage; requires direct contract privity between the Named Insured and the Additional Insured.
CG 20 38 04 13	Additional Insured – Owners, Lessees or Contractors – Automatic Status for Other Parties	Ongoing operations only	Blanket automatic coverage that also covers upstream parties (such as a building owner when a GC hires a sub) without direct privity.
CG 20 01 04 13	Primary and Noncontributory – Other Insurance Condition	Modifies priority of coverage	Ensures the vendor's GL policy pays first (Primary) without seeking contribution (Noncontributory) from the Additional Insured's own policy.

Worked Example: High-Risk Trade Benchmark Verification

Consider a construction or major capital repair contract where Harborview Property Management Inc. hires Apex Plumbing LLC on behalf of 123 Main Street Holdings LLC. Under the General Contractor / High-Risk Trade preset benchmark:

• General Liability Limits: $2,000,000 Each Occurrence / $4,000,000 General Aggregate / $4,000,000 Products-Completed Operations Aggregate.
• Required Endorsements: CG 20 10 04 13 (ongoing operations) and CG 20 37 04 13 (completed operations), plus Primary and Non-Contributory wording.

When Apex Plumbing LLC's broker uploads their PDF packet through the self-serve vendor upload portal, review three specific details on the attached CG 20 10 04 13 and CG 20 37 04 13 pages:

1. Schedule Box Completion: Does the "Name Of Additional Insured Person(s) Or Organization(s)" box name both 123 Main Street Holdings LLC and Harborview Property Management Inc., or contain blanket contract language?
2. Location of Covered Operations: Does the location box specify the property address (123 Main Street) or state "All Locations Where Required by Written Contract"?
3. Edition Date Limitations (04 13 / 12 19): Note that 04 13 and 12 19 editions include two important limitations: coverage applies only to the extent permitted by law (respecting state anti-indemnity statutes) and will not be broader than the coverage and dollar limits required by your written contract.

Watch Out for Direct Privity Traps on Blanket Forms

If a subcontractor submits CG 20 33 instead of CG 20 10, look closely at who signed the contract. CG 20 33 grants automatic Additional Insured status only to an organization with whom the subcontractor has agreed in writing in a contract or agreement directly. If a General Contractor signs the subcontract with Apex Plumbing LLC, CG 20 33 covers the General Contractor—but may leave the upstream property owner (123 Main Street Holdings LLC) without Additional Insured status unless CG 20 38 or a scheduled CG 20 10 is also present.

Verify CG 20 10 and CG 20 37 in Seconds

Built for subcontractor COI tracking and COI tracking for property management, COIScreen inspects ACORD 25 forms and endorsement pages side by side. Upload your vendor PDF now to check an ACORD 25 certificate for free.