An "additional insured" is a person or organization added to your Commercial General Liability policy so they receive coverage and a legal defense under your policy. The two most-used ISO endorsements are CG 20 10 — Additional Insured – Owners, Lessees or Contractors – Scheduled Person Or Organization, which covers the additional insured for your ongoing operations — and CG 20 37, which extends it to completed operations. Contractors typically need both. Being an additional insured is very different from being a certificate holder: an additional insured gets actual coverage; a certificate holder only receives proof of insurance.
"Add us as an additional insured" is the single most common insurance request in commercial contracts — from general contractors, landlords, and clients. It means more than handing over a certificate: it changes who your policy actually protects. This guide explains CG 20 10 vs CG 20 37, the 2013 edition change, and why an additional insured is not the same as a certificate holder. Source: IRMI additional insured reference + "2013 ISO Additional Insured Endorsements"; IRMI certificate holder; NAIC.
operations
operations
(vs cert holder)
ISO edition change
What is an additional insured?
An additional insured is a person or organization not automatically insured under a policy who is added to it at the named insured's request — usually to satisfy a contract. Once added, the additional insured gets coverage and a defense under your policy for liability arising out of your work or premises.
- It's contractual — a general contractor requires subs to add the GC; a landlord requires a tenant to add the landlord; a client requires a vendor to add the client.
- It shifts risk down the chain — the additional insured taps the other party's policy first, protecting their own loss history and limits.
- It's added by endorsement — the base CG 00 01 CGL form doesn't automatically cover these parties; an endorsement (CG 20 10 / CG 20 37 and relatives) does.
CG 20 10 vs CG 20 37 (ongoing vs completed operations)
These two endorsements are the workhorses of construction and vendor contracts, and they cover different phases of the work — which is why savvy contracts require both.
| Endorsement | Full name | Covers the additional insured for… |
|---|---|---|
| CG 20 10 | Additional Insured – Owners, Lessees or Contractors – Scheduled Person Or Organization | Ongoing operations — liability while the work is being performed. |
| CG 20 37 | Additional Insured – Owners, Lessees or Contractors – Completed Operations | Completed operations — liability from the finished work after the job ends. |
Contractors usually need both. CG 20 10 alone leaves the additional insured unprotected for claims that surface after the project is done — exactly when many construction-defect claims appear. Pairing CG 20 10 + CG 20 37 covers both phases.
Additional insured vs certificate holder
This is the most expensive misunderstanding in commercial insurance. They are not the same, and a certificate holder has almost no rights.
| Additional insured | Certificate holder | |
|---|---|---|
| What they get | Actual coverage + a defense under the policy | A copy of the certificate — proof the policy exists |
| How it's created | An endorsement (CG 20 10 / CG 20 37) added to the policy | Simply listed on the certificate of insurance |
| Can they file a claim? | Yes — they're an insured | No — the certificate confers no coverage or rights |
If your contract says "additional insured," a certificate listing you as certificate holder is not enough — you need the actual endorsement on the policy.
The 2013 ISO edition change
In 2013, ISO revised the additional-insured endorsements. Two practical effects: coverage was tied more explicitly to liability caused by the named insured (rather than merely "arising out of" their work), and the endorsements were aligned so the additional insured's coverage does not exceed what the contract requires or what the law allows. The edition date on the endorsement (e.g., CG 20 10 04 13) tells you which version applies.
The full "AI package" (primary & non-contributory, waiver)
Most contracts ask for more than just additional-insured status. The common package:
- Additional insured (CG 20 10 + CG 20 37) — coverage for ongoing + completed operations.
- Primary & non-contributory — your policy pays first, and doesn't ask the additional insured's own policy to contribute.
- Waiver of subrogation — your insurer waives its right to recover from the additional insured after paying a claim.
All three are endorsements on your general liability policy and typically show up together in a well-drafted contract's insurance requirements.
Who asks for it — and who provides it
- General contractors → subcontractors — the GC requires subs to name the GC (and often the owner) as additional insureds for the project.
- Landlords → tenants — commercial leases require the tenant to add the landlord and property manager.
- Clients → vendors — service agreements require the vendor to add the client.
- You provide it by asking your agent to add the endorsement to your GL/BOP and issuing a certificate that references it.
Frequently Asked Questions
What is an additional insured?
An additional insured is a person or organization added to your insurance policy — usually by endorsement, to satisfy a contract — so they receive coverage and a legal defense under your policy for liability arising out of your work or premises. It's how a general contractor, landlord, or client gets protection under your policy.
What is the difference between CG 20 10 and CG 20 37?
CG 20 10 adds an additional insured for your ONGOING operations (liability while the work is being performed). CG 20 37 adds them for COMPLETED operations (liability from the finished work after the job ends). Contractors usually need both, because many construction-defect claims surface after a project is done — which CG 20 10 alone would not cover for the additional insured.
Is a certificate holder the same as an additional insured?
No — and this is a costly misunderstanding. An additional insured is added to the policy by endorsement and actually receives coverage and a defense. A certificate holder simply receives a copy of the certificate of insurance as proof the policy exists; the certificate confers no coverage or rights. If your contract requires additional-insured status, a certificate listing you as certificate holder is not enough — you need the endorsement on the policy.
Do I need both CG 20 10 and CG 20 37?
Usually yes for construction and similar work. CG 20 10 covers the additional insured during ongoing operations; CG 20 37 extends coverage to completed operations. Because completed-work (construction-defect) claims often appear after the job is finished, well-drafted contracts require both so the additional insured is protected in both phases.
What does 'primary and non-contributory' mean with additional insured status?
It means your policy pays first (primary) and does not ask the additional insured's own insurance to contribute (non-contributory). Contracts commonly require additional-insured status plus primary & non-contributory wording plus a waiver of subrogation — together, this shifts the risk of a claim from the additional insured onto your policy.
How do I add someone as an additional insured?
Ask your agent to add the appropriate endorsement (CG 20 10 for ongoing operations, CG 20 37 for completed operations, and any primary & non-contributory / waiver endorsements the contract requires) to your general liability or BOP policy. Then issue a certificate of insurance that references the endorsement. There is sometimes a small premium for broad additional-insured endorsements.
Quick glossary — additional insured terms
- Additional Insured
- A party added to a policy by endorsement so it receives coverage and a defense under that policy.
- CG 20 10
- ISO additional-insured endorsement for owners, lessees or contractors — ongoing operations.
- CG 20 37
- ISO additional-insured endorsement for owners, lessees or contractors — completed operations.
- Ongoing Operations
- Liability arising while the work is being performed.
- Completed Operations
- Liability arising from finished work after the job is done.
- Primary & Non-Contributory
- Your policy pays first and does not seek contribution from the additional insured's own policy.
- Waiver of Subrogation
- Your insurer gives up its right to recover from a named party after paying a claim.
- Certificate Holder
- A party that receives a certificate of insurance as proof — not an insured, and not covered by the policy.