Additional insured status comes from an endorsement, and the endorsements are not interchangeable. The check box on a certificate is a claim that one of them exists. Which form you have decides whether your client is covered during the work, after the work, or not at all. Who this is for: anyone required to name a client as an additional insured.
The short version
- Ongoing operations and completed operations are two different endorsements.
- Construction and installation work needs both, because defect claims arrive after the job ends.
- Standard forms cover the other party for your work, not for their own independent negligence.
- Older edition forms are broader than current ones, which is why edition dates matter.
- Additional insureds share your limits rather than adding to them.
The forms you will see cited
| Form | What it covers | When you need it |
|---|---|---|
| Form CG 20 10 | The other party for liability arising from your ongoing operations | Almost every service contract |
| Form CG 20 37 | The other party for claims arising after your work is complete | Construction, installation, and anything with a defect tail |
| Forms CG 20 33 and CG 20 38 | Blanket wording covering anyone you agreed in writing to name | Businesses signing many contracts |
| Form CG 20 26 | A named party for your operations generally, without requiring a written contract | Occasionally requested by owners |
| Form CG 20 01 | Primary and non contributory wording | Whenever the contract uses those words |
| Carrier proprietary forms | Varies, sometimes broader and sometimes narrower | Read it rather than assuming it matches an industry form |
The completed operations trap
A certificate showing additional insured status with only ongoing operations wording satisfies a contract on paper and fails when it matters. Most construction claims arrive after the project closes: a roof leaks, a joint fails, a floor moves. If the endorsement stopped at substantial completion, the party relying on it is on its own for exactly the claims it was most worried about.
If your contract says additional insured without specifying, ask for both. The additional premium is usually modest and the gap it closes is the expensive one.
What these endorsements do not do
- They do not cover the other party's sole negligence on current standard forms.
- They do not increase your limits. Everyone named shares the same limit.
- They do not apply to professional liability, which is a separate policy most carriers will not endorse this way.
- They do not survive a policy that has been cancelled or exhausted.
What to ask your broker
- Which additional insured endorsements are on my policy today, by form number and edition date?
- Is the wording blanket or scheduled?
- Does it include completed operations?
- Does my umbrella follow the same wording?
- Can I get copies of the endorsement forms to send with certificates?
Related reading: what an additional insured is and why clients ask.
What this looks like in practice
Illustrative example. It is typical of what we see and is not a promise of how any specific situation would be handled.
The setup: A siding contractor names a general contractor as an additional insured using ongoing operations wording only.
What went wrong: A water intrusion claim surfaced fourteen months after the project was completed, and the endorsement no longer applied.
What it cost: The general contractor defended itself and then pursued the siding contractor directly for roughly $180,000, uninsured on that side.
The fix: Ask for completed operations additional insured wording on any work that can fail after it is finished, which is most construction and installation work.
Frequently asked questions
Q: What is an additional insured endorsement?
An amendment to your policy that extends coverage to another party for liability arising out of your work. It is what actually gives them protection, unlike the certificate that reports it.
Q: What is the difference between the ongoing and completed operations forms?
The ongoing operations form covers the other party while you are working. The completed operations form covers them for claims arising after your work is finished. Construction contracts usually need both.
Q: Does an additional insured endorsement cover the other party's own negligence?
Not on current standard forms. Coverage is limited to liability arising out of your work. Some older editions and some proprietary forms are broader, which is why the edition date matters.
Q: Do additional insureds get their own limits?
No. They share yours. If a claim exhausts the limit defending and indemnifying an additional insured, there is less left for you, which is an argument for higher limits.
Q: How much does an additional insured endorsement cost?
Often nothing, especially where blanket wording already exists. Completed operations coverage sometimes carries a modest additional premium depending on the trade.
Q: Can I add an additional insured to my professional liability policy?
Usually not. Most professional liability carriers do not offer it. The practical answer is to provide it on general liability and auto and give the client a certificate for the professional line.
How Morrow helps with certificates of insurance
Morrow is a licensed independent commercial insurance brokerage that specializes in certificates of insurance and the endorsements behind them. Confirming which additional insured forms are actually on your policy is the kind of thing we handle every day, for clients across construction, trades, professional services, trucking, real estate, and hospitality, so we know what a compliance reviewer will reject before you send it.
- We issue certificates the same day you ask, and usually within the hour.
- We read the contract first, so the endorsements the certificate reports actually exist on your policy.
- We push back on requirements the market will not issue, and give you language your client will accept.
- We keep a record of who was issued what, so renewals go out before anyone chases you.
Get in touch and we will see how we can help. Send us the contract or the certificate request and we will tell you what your current policy can support and what needs to change. Start at morrowinsure.com or reach the team through the contact options on that page.
One more thing. This article is general information and is not legal advice or a statement of coverage. Certificates report what a policy says, and the policy wording controls in every case. Forms and requirements vary by carrier, by state, and by contract, so have a licensed advisor review your own policy and your own contract before relying on any of it.
Last updated: Reviewed by the Morrow commercial lines team. Last updated August 2026.