Additional Insured, Primary & Noncontributory, and Waiver of Subrogation: What Your GC Is Really Asking For

Short answer: When a general contractor asks for AI, PNC, and WOS, they are asking you to add three specific endorsements to your General Liability policy — Additional Insured (typically ISO forms CG 20 10 / CG 20 37), Primary and Noncontributory (CG 20 01), and Waiver of Subrogation (CG 24 04) — so your insurance responds first to claims arising from your work, and your carrier waives its right to recover from the GC after paying that claim.

Reviewed by Pascal Burke, Licensed Commercial Insurance Broker (CA #6015321, TX #3305690) · Last reviewed: May 17, 2026 · Sources: ISO, IRMI, Insurance Information Institute

Endorsement	Common ISO Form	What It Does (One Sentence)	Typical Annual Cost
Additional Insured (AI)	CG 20 10 (ongoing) / CG 20 37 (completed)	Adds the GC or owner to your General Liability policy so it can respond to claims arising from your work.	$50 to $300
Primary and Noncontributory (PNC)	CG 20 01	Makes your policy pay first and stops the GC’s carrier from being asked to share the loss.	$0 to $200
Waiver of Subrogation (WOS)	CG 24 04	Prevents your carrier from pursuing the GC for reimbursement after paying a claim tied to your work.	$50 to $250

Costs are illustrative ranges and vary by carrier, class code, state, and underwriting profile.

TLDR: The Three Endorsements in One Glance

When a general contractor asks for “AI, PNC, and WOS,” they are not speaking insurance jargon to confuse you. They are asking for three specific risk-transfer tools:

Endorsement	What It Does
Additional Insured (AI)	Adds the GC to your policy so your insurance can respond to claims tied to your work
Primary and Noncontributory (PNC)	Your policy pays first, not the GC’s
Waiver of Subrogation (WOS)	Your carrier gives up the right to sue the GC after paying a claim

If even one is missing, your COI may not satisfy the contract requirements. Industry references: IRMI, Insurance Information Institute, ISO.

Why GCs Demand These Three Endorsements

Risk Transfer in the Subcontract

Every subcontract is a risk transfer agreement. The GC is generally trying to ensure that if something goes wrong on your scope of work, your insurance responds first, not theirs. That structure is standard across commercial construction contracts.

How a GC’s Insurance Stack Actually Works

A GC typically relies on:

• Their own General Liability policy
• Project-level risk controls
• Subcontractor insurance requirements

Your endorsements plug into that structure so their carrier is generally not pulled into your claim first.

Why a Plain COI Isn’t Enough

A Certificate of Insurance (COI) only shows coverage exists. It generally does not confirm:

• Who is insured beyond the named insured
• Which policy responds first
• Whether the GC is protected under your policy

For COI guidance, see our Certificate of Insurance compliance overview.

💬 Broker’s Note (Pascal Burke): The COI vs endorsement confusion is the single most common gap I see in bid review. A contractor sends in a COI showing the GC as Certificate Holder and assumes that satisfies the “additional insured” requirement. It does not. The Certificate Holder line is informational only. The actual additional insured status comes from the endorsement attached to the policy, and the COI should reference that endorsement form by number.

Additional Insured (AI), Explained

What “Additional Insured” Actually Means on Your Policy

Additional Insured generally means the GC or owner is added to your General Liability policy for liability arising out of your work. It is typically issued through ISO forms such as:

• CG 20 10 (ongoing operations)
• CG 20 37 (completed operations)

Reference: ISO and IRMI.

Blanket vs Scheduled AI Endorsements

• Blanket AI: Automatically covers qualifying contract parties under defined criteria (typically “as required by written contract”)
• Scheduled AI: Requires naming each GC or project specifically

Blanket AI is generally preferred for subcontractors working multiple jobs, but availability and pricing depend on carrier and underwriting.

Ongoing Operations vs Completed Operations

• Ongoing operations: Work currently in progress
• Completed operations: Liability after the job is finished

Many GCs require both, especially on commercial projects.

Common AI Endorsement Forms

Form	Coverage
CG 20 10	Adds AI during active work (ongoing operations)
CG 20 37	Extends AI to completed operations
Custom blanket forms	Carrier-specific blanket AI structures

Note: ISO form edition dates (e.g., 04 13, 12 19) change periodically and may affect specific coverage terms. Confirm current edition with your broker.

What Your AI Endorsement Should Say

Most GCs are looking for language confirming:

• “Additional Insured status for ongoing and completed operations”
• “Per written contract” or similar wording tied to the subcontract agreement

💬 Broker’s Note (Pascal Burke): The most common mistake I see is contractors assuming “additional insured” is one universal form. It is not. CG 20 10 covers ongoing operations, but if your contract requires completed operations and you only have CG 20 10, you may still be noncompliant even though your COI looks correct.

Primary and Noncontributory (PNC), Explained

What “Primary” Means

Primary generally means your insurance responds first in a claim involving your work. The GC’s policy does not step in until your limits are exhausted.

What “Noncontributory” Means

Noncontributory generally means:

• The GC’s insurance does not share the loss payment
• Your policy does not “split” the claim with theirs

Why GCs Want Both Together

GCs want clean separation:

• Your work = your insurance
• Their policy = last resort only

How PNC Shows Up on Your Policy

PNC is typically added through:

• ISO CG 20 01 form
• Carrier-specific endorsement wording

Reference: IRMI and Insurance Information Institute. For more on PNC structure, see our Primary and Noncontributory compliance page.

Waiver of Subrogation (WOS), Explained

What “Subrogation” Actually Is

Subrogation is the right of your insurance carrier to recover money from a responsible third party after paying a claim.

How a Waiver Limits Your Carrier’s Recovery Rights

A Waiver of Subrogation generally means your carrier agrees not to pursue the GC or project owner after paying a claim related to your work.

Why GCs Want WOS in the Subcontract

GCs generally want to avoid being pulled into:

• Carrier reimbursement claims
• Cross-litigation between insurers
• Recovery actions after jobsite incidents

Blanket vs Scheduled Waivers

• Blanket WOS: Applies to all contracts automatically under defined criteria
• Scheduled WOS: Applies only to named parties or projects

ISO Form Reference

• CG 24 04 is a common ISO Waiver of Subrogation form for General Liability
• Workers’ compensation waivers are governed separately by state rules and require carrier filing

State authority references:

• Texas Department of Insurance (TDI)
• California Department of Insurance (CDI)

For more on WOS, see our Waiver of Subrogation compliance page.

💬 Broker’s Note (Pascal Burke): A key misunderstanding is assuming Waiver of Subrogation works the same across all policy types. It does not. On General Liability, it is contract-driven through forms like CG 24 04. On Workers’ Compensation, it is regulated at the state level and requires separate carrier filing. That difference is where many contractors get confused during bid review — they have a GL waiver in place and assume it covers WC, when in fact a separate WC waiver may be needed.

How These Three Endorsements Work Together

Quick Answers to Common Endorsement Questions

What is the difference between CG 20 10 and CG 20 37?

CG 20 10 adds the general contractor or project owner as an Additional Insured on your General Liability policy during ongoing operations — the active phase of your work on the project. CG 20 37 extends Additional Insured status to completed operations, which is the liability tail after your work is finished and the project is in service. Many GCs require both forms, especially on commercial projects, because a defect or injury can be discovered months or years after the job is complete.

Does a General Liability Waiver of Subrogation cover Workers’ Compensation claims?

No. A Waiver of Subrogation on a General Liability policy (typically ISO CG 24 04) only waives the GL carrier’s recovery rights for GL claims. Workers’ Compensation waivers are governed by state insurance regulations and require a separate state-filed endorsement through the Workers’ Compensation carrier. If your subcontract requires WOS for both lines of coverage, you generally need two distinct endorsements — one on the GL policy and one on the WC policy.

What is a blanket Additional Insured endorsement and when is it preferred?

A blanket Additional Insured endorsement automatically extends Additional Insured status to any party the named insured is required by written contract to add, without listing each party individually on the policy. Blanket AI is generally preferred by subcontractors working multiple jobs because it eliminates the administrative burden of scheduling each GC, and it ensures coverage is in place as soon as the subcontract is signed. Availability, wording, and cost vary by carrier and underwriting class.

What happens if my subcontract requires AI, PNC, and WOS but my current policy does not support all three?

If your existing carrier cannot issue one or more of the required endorsements, options generally include: requesting an alternate endorsement form that achieves equivalent coverage, negotiating a contract amendment with the GC, moving the policy to a carrier that supports the required structure, or restructuring the policy at renewal. Walking away from a job over a single endorsement gap is rarely necessary if the issue is identified early; bring the bid packet to your broker before signing the subcontract so alternatives can be explored.