Primary and Noncontributory: What It Means on a COI

Last updated July 2026.

Primary and noncontributory means the vendor's insurance pays first and in full for a covered claim, without asking your own policy to chip in. Primary means their coverage responds before yours. Noncontributory means their insurer will not demand that your insurer share the loss. Contracts require it so a vendor's claim is paid by the vendor's insurance, not yours, which keeps your limits and your loss history intact.

Primary and noncontributory is one of the three requirements risk managers put alongside additional insured status and waiver of subrogation on almost every vendor contract. It is easy to require and easy to get wrong, because the phrase on a certificate is not the same as the endorsement on the policy. Here is what it means and how to confirm you actually have it.

What does primary and noncontributory mean?

Primary means the vendor's policy is the first layer of coverage to respond to a claim it applies to, before your own policy is touched. Noncontributory means the vendor's insurer agrees not to seek contribution from your insurer, even though you may carry coverage for the same loss. Without this language, two insurers can argue over who pays what, your policy can be dragged in, and your premiums and loss runs take the hit for something a vendor caused.

What is the primary and noncontributory endorsement?

The requirement is made real by an endorsement on the vendor's general liability policy. The ISO form is CG 20 01, titled Primary And Noncontributory, Other Insurance Condition, which adds a paragraph to the policy's Other Insurance condition stating the insurance is primary to and will not seek contribution from other insurance available to an additional insured. The commercial auto equivalent is CA 04 49. Some insurers use their own manuscript wording. Either way, the endorsement, not the sentence typed on the certificate, is what obligates the insurer.

The form itself carries two conditions that both have to be true before the insurer gives anything up, and the current 12 19 edition differs from 04 13 in one specific way. Our primary and noncontributory endorsement forms reference quotes the wording of CG 20 01 and CA 04 49 directly from issued forms and compares the editions side by side.

Why do contracts require primary and noncontributory coverage?

Because additional insured status alone is not enough. You can be an additional insured on a vendor's policy and still have your own insurance pulled into a claim if the policies are treated as sharing the loss. Primary and noncontributory closes that gap: it forces the vendor's coverage to stand in front of yours and stay there. For a general contractor or property owner facing dozens of vendors, that difference is what keeps one subcontractor's accident from quietly eroding your program.

Is primary and noncontributory the same as additional insured?

No. They are two separate requirements that work together. Additional insured status puts you on the vendor's policy so it will defend and indemnify you. Primary and noncontributory controls the order of payment so that the vendor's policy, not yours, actually pays. You want both, plus a waiver of subrogation, and each is backed by its own endorsement. Which form creates which is set out in the waiver of subrogation endorsement forms reference. The distinction between being named and being a certificate holder is covered in additional insured vs certificate holder.

Does primary and noncontributory need an endorsement?

Yes, to be reliable it needs an endorsement on the vendor's policy. A line in the description of operations box of an ACORD 25 stating coverage is primary and noncontributory is a representation, not a contract term the insurer is bound to. If there is a dispute, the insurer looks at its policy and its endorsements, not the certificate. Require the CG 20 01 or an equivalent endorsement and get a copy, the same way you would for additional insured and waiver of subrogation.

What happens without primary and noncontributory coverage?

Without it, a claim you expected the vendor to cover can end up shared between their insurer and yours under standard other insurance rules. Even as an additional insured, if both policies are treated as contributing, your insurer pays part of the loss, your loss runs record the claim, and your renewal premium can rise for damage a vendor caused. In a bad case, the vendor's insurer argues its coverage is excess over yours and pays little or nothing until your limits are exhausted. Primary and noncontributory language is what stops that argument before it starts, which is why lenders, landlords and general contractors treat it as non negotiable rather than a nice to have.

How do you verify primary and noncontributory on a COI?

Start by accepting that the certificate cannot answer this for you. The ACORD 25 grid has exactly two endorsement columns, ADDL INSR and SUBR WVD. There is no column for primary and noncontributory anywhere on the form, so the only place it can appear is as free text in the Description of Operations box, and only if the person preparing the certificate thought to type it. Reviewers who work down the checkbox columns approve vendors who never bought CG 20 01, and nothing on the document looks wrong.

So ask for the endorsement by form number, then confirm three things: that the form is attached to the correct policy, that it applies where a written contract requires it, and that the policy is current. Commercial leases and construction contracts usually spell out all three insurance requirements in the same section, and if you are working from a long lease you can pull the insurance clauses straight out of the document so you know exactly what to check the certificate against. Then match the vendor's endorsements to those requirements on every renewal, not just at signing.

Common mistakes with primary and noncontributory

Three errors show up again and again. The first is treating the certificate wording as proof and never requesting the endorsement, so the requirement exists on paper but not in the policy. The second is confirming it once at contract signing and never rechecking, so a policy that dropped the endorsement at renewal goes unnoticed until a claim. The third is confusing the three requirements and assuming additional insured status covers the payment order too, when it does not. Requiring the endorsement in writing, getting a copy, and rechecking every renewal fixes all three.

Build it into your compliance checks

Primary and noncontributory is only worth requiring if you verify it every time a certificate renews. Set it as a rule alongside your additional insured and waiver of subrogation requirements, and check each arriving certificate against all three. That is what vendor insurance compliance software does automatically, and it is how subcontractor COI tracking catches a policy that dropped the endorsement at renewal before it becomes your uncovered claim. The related waiver requirement is explained in waiver of subrogation on a certificate of insurance, and every form you are likely to see listed next to CG 20 01 is set out in our guide to certificate of insurance endorsements.