an article by Noelle McCall, CIC, CRM, CCIP, CRP, ACRA, CISR

A few years ago, a GC hired a plumbing subcontractor for a major commercial build. As part of their contract, the GC required the plumber to add them as an additional insured on the plumber’s general liability policy. So far, so good, right?

But here’s the problem: the contract didn’t specify which additional insured forms were required. The plumber’s insurer issued the CG 20 10 12 19 endorsement - but that version only covered liability for work while the work was being performed. It didn’t include completed operations coverage.

Fast forward 18 months. A pipe installed by the plumber failed after the building was turned over to the owner, causing hundreds of thousands in water damage. When the GC filed a claim under the plumber’s policy, coverage was denied. Why? Because the CG 20 10 12 19 form didn’t provide completed operations coverage. As a result, the GC was left holding the bag.

This kind of mistake is more common than you might think.

Here’s How to Get It Right

If you’re involved in negotiating construction contracts you need to be precise about which additional insured endorsement is required.

There’s no one-size-fits-all. Different forms provide different types of coverage and use of the wrong one can leave you without protection when you need it most.

For Ongoing Operations:

• Use CG 20 38 12 19 or CG 20 10 12 19
  These forms provide coverage while the subcontractor is performing work on the job site. This is known as ongoing operations coverage.

For Completed Operations:

• Use CG 20 40 12 19 or CG 20 37 12 19
  This endorsement is critical for claims that arise after the work is done (like the leaking pipe example).

✅ Make sure you require additional insured forms that cover both ongoing and completed operations.

Why It Matters

If the contract doesn’t specify which additional insured forms are required, then subcontractors might default to using a version that doesn’t provide the scope of coverage needed. And once the subcontractor’s policy has been issued, it’s harder to change to add required endorsements. You don’t want to find out after a loss that the coverage you thought you had as an additional insured doesn’t exist on the policy.

A few things you can do:

• Be specific in your insurance requirements: list the form numbers and edition dates.
• Request and review the endorsements - not just the certificate of insurance.
• Educate your team (and your clients) on why it is critical to require specific additional insured forms. It’s not just insurance jargon. It’s real protection for real risk.

If you work with construction clients or negotiate these contracts yourself, make sure this language is dialed in. The devil really is in the details here.