Primary And Noncontributory — Other Insurance Condition
Makes the sub's CGL pay first and not seek contribution from the GC's own policy.
What it actually does
CG 20 01 amends the "Other Insurance" condition of the CGL so that the named insured's coverage is primary, and will not seek contribution from, another policy on which a person or organization is an additional insured — but only when a written contract requires the coverage to be primary and noncontributory.
This is the form that satisfies the "primary and non-contributory" requirement GCs put in nearly every subcontract. Without it, the sub's insurer could argue the GC's own CGL should share the loss pro rata, which delays claims and can pull down the GC's limits and loss history. CG 20 01 makes the sub's policy pay first and stand alone for the additional insured.
It works alongside the additional-insured endorsement (you need both AI status and primary-noncontributory wording); CG 20 01 does not by itself make anyone an additional insured. Verify it's attached whenever the subcontract demands primary and noncontributory coverage.
Verification checklist
- 01Confirm CG 20 01 is actually attached — a checked COI box is not the endorsement.
- 02Confirm an additional-insured endorsement (CG 20 10/37/38) is also present; CG 20 01 doesn't grant AI status by itself.
- 03Verify the subcontract requires primary and noncontributory coverage (the form is conditioned on that).
- 04Check the policy period covers the work.
Which edition do you have?
ISO introduced CG 20 01 in the 04 13 program so a single standard form could satisfy the near-universal "primary and noncontributory" contract requirement (previously handled by manuscript wording). It conditions the primary-noncontributory treatment on a written contract requiring it, executed before the loss.
Common mistakes
- ·Treating CG 20 01 as additional-insured coverage — it's only the other-insurance amendment; you still need an AI form.
- ·Relying on the COI's 'primary & noncontributory' checkbox without the actual endorsement.
Frequently asked questions
What does primary and noncontributory mean?
Primary means the sub's policy pays first; noncontributory means it won't demand the GC's own insurer share the loss pro rata. CG 20 01 makes the sub's CGL behave that way for the additional insured.
Does CG 20 01 make the GC an additional insured?
No. It only amends the other-insurance condition. You still need an additional-insured endorsement (CG 20 10/37/38) alongside it.
Is a checkbox on the COI enough for primary & noncontributory?
No. The CG 20 01 endorsement (or equivalent policy wording) must actually be attached; the COI box is informational only.
Checking a COI for CG 20 01?
Upload it free — we'll tell you whether CG 20 01 is actually attached, the right edition, and scheduled correctly, plus every other gap against your requirements.
Check a COI for CG 20 01 →Related endorsements
This page explains CG 20 01 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.