What Does Primary And Noncontributory Mean On A COI?
Why GCs require it, how it works with additional-insured status, and the form that grants it.
What it actually does
"Primary and noncontributory" describes how two policies interact when both could respond to the same loss. *Primary* means the subcontractor's policy pays first, before any coverage the GC carries. *Noncontributory* means the sub's insurer won't demand that the GC's own insurer chip in pro rata. Together they ensure the sub's policy fully absorbs a loss connected to the sub's work, rather than sharing it with — and eroding — the GC's coverage.
GCs require this in nearly every subcontract because the alternative is messy: without it, the sub's insurer can argue the GC's CGL should contribute, which slows claims, pulls the GC's limits into the loss, and damages the GC's loss history. The standard ISO form that delivers it is CG 20 01, which amends the policy's "Other Insurance" condition when a written contract requires primary-and-noncontributory treatment.
Crucially, primary-and-noncontributory wording works *alongside* additional-insured status — it doesn't grant AI status by itself. You need both the AI endorsement (CG 20 10/37/38) and the CG 20 01 wording, and you should confirm both are actually attached rather than trusting the COI checkboxes.
Verification checklist
- 01Confirm CG 20 01 (or equivalent primary-noncontributory wording) is actually attached.
- 02Confirm an additional-insured endorsement is also present — CG 20 01 doesn't grant AI status.
- 03Verify the subcontract requires primary & noncontributory (the form is conditioned on that).
- 04Don't rely on the COI 'primary & noncontributory' checkbox alone.
Common mistakes
- ·Assuming primary-noncontributory wording makes you an additional insured — it doesn't.
- ·Relying on the COI checkbox without the CG 20 01 endorsement attached.
Frequently asked questions
What does primary and noncontributory mean?
Primary means the sub's policy pays first; noncontributory means it won't make your insurer share the loss pro rata. Together they keep a loss on the sub's policy instead of eroding yours.
What form provides primary and noncontributory?
CG 20 01 amends the CGL's other-insurance condition to make coverage primary and noncontributory when a written contract requires it.
Does it replace additional-insured status?
No. You need both — the additional-insured endorsement and the primary-and-noncontributory wording. CG 20 01 alone grants no AI status.
Checking a sub's COI right now?
Upload it free — we'll check every endorsement, edition, and limit against your requirements and hand back a per-vendor gap report.
Run a free COI audit →Related endorsements
This page explains Primary & Noncontributory (Explained) in plain English for COI verification. It is informational only and is not legal or insurance advice — confirm the actual endorsement language and have your counsel or insurance agent review your specific requirements.