Commercial General Liability (CGL): Definition and How It Works

Commercial General Liability (CGL) insurance is the foundational liability coverage for most businesses, protecting them against claims from third parties alleging bodily injury (BI), property damage (PD), personal injury, and advertising injury arising from the business's operations, products, and premises. The standard CGL policy is issued on ISO form CG 00 01 and is one of the most widely placed commercial insurance products. For insurance brokers, the CGL is the starting point for nearly every commercial lines account — the baseline layer of protection around which specialized coverages (workers' compensation, commercial auto, professional liability, cyber) are added. Understanding what CGL covers, what it excludes, and how its limits work is fundamental to sound commercial insurance placement.

What a CGL Policy Covers

A standard ISO CGL policy provides three coverage parts:

Coverage A — Bodily Injury and Property Damage Liability

Covers the insured's legal liability for claims by third parties alleging physical injury to persons or damage to tangible property caused by the insured's operations, products, or premises. Common examples:

• A customer slips and falls on the insured's business premises (premises and operations)
• A contractor damages a client's property while performing work (operations)
• A product manufactured by the insured causes injury after sale (products liability)
• Work performed by the insured causes damage that becomes apparent after project completion (completed operations)

Coverage A uses an occurrence trigger in the standard ISO form — the policy covers incidents that occur during the policy period, regardless of when the claim is filed. (The claims-made trigger is available for some lines but less common for CGL.) For the distinction between occurrence and claims-made triggers, see Occurrence Policy and Claims-Made Policy.

Coverage B — Personal and Advertising Injury Liability

Covers non-physical harms arising from the insured's business activities:

• Personal injury: False arrest, wrongful eviction, malicious prosecution, libel, slander, violation of privacy rights
• Advertising injury: Copyright infringement in advertising, slogan misappropriation, misappropriation of advertising ideas

Coverage B is often overlooked in client presentations but provides important protection for businesses that advertise, create content, or have customer-facing communications.

Coverage C — Medical Payments

Covers medical expenses for bodily injuries sustained by third parties on the insured's premises or arising from the insured's operations, regardless of fault — up to the medical payments limit (typically $5,000–$10,000). Medical payments is a goodwill coverage that allows prompt payment of minor injuries without a liability determination or formal claim process.

Standard CGL Limits Structure

A CGL policy has multiple sublimits within an overall aggregate:

The general aggregate resets annually with each policy renewal — prior-year claims do not erode the current-year aggregate.

Key CGL Exclusions

What a CGL policy does not cover is as important as what it covers:

• Professional services exclusion: Claims arising from professional advice, errors, or omissions — this gap requires a separate Errors and Omissions Insurance or professional liability policy. See CGL vs Professional Liability (E&O) for the complete coverage gap analysis.
• Workers' compensation exclusion: Employee injuries are excluded from CGL — covered by workers' compensation and employer's liability instead
• Intentional acts: Claims arising from deliberate harm
• Pollution: Most standard CGL forms include a broad pollution exclusion eliminating coverage for environmental contamination — contractors and industrial clients may need a separate pollution liability policy
• PFAS: ISO endorsements excluding PFAS contamination claims are now standard on CGL forms for businesses with PFAS exposure — particularly manufacturing, fire suppression, and food processing. See PFAS Exclusions in Commercial Insurance.
• Auto liability: Owned, hired, and non-owned autos require separate commercial auto coverage
• Employment practices: Wrongful termination, discrimination, and harassment require a separate EPLI policy
• Cyber liability: Data breaches and network attacks are excluded from standard CGL; a standalone cyber policy is required

CGL and the Additional Insured Endorsement

One of the most frequently used CGL mechanics in commercial practice is the additional insured endorsement. General contractors, property owners, and clients routinely require contractors, vendors, and tenants to add them as additional insureds on the CGL policy — receiving coverage for their vicarious liability arising from the named insured's operations. Additional insured status is granted by endorsement (ISO CG 20 10, CG 20 37, or negotiated manuscript forms) and is subject to the scope and limits of the underlying CGL policy. For a full explanation, see Additional Insured.

CGL Within a Business Owners Policy (BOP)

For eligible small and mid-size businesses, CGL coverage is typically packaged within a Business Owners Policy (BOP) rather than issued as a standalone commercial package. The BOP combines CGL, commercial property, and business income coverage in a single form at a discount. For larger, more complex commercial risks that don't qualify for BOP eligibility, CGL is written as a standalone coverage part within a Commercial Package Policy (CPP). See Business Owners Policy.

Related Terms

• Occurrence Policy — CGL is almost always written on an occurrence trigger; understanding this is critical to coverage analysis
• Umbrella Insurance — umbrella and excess liability policies sit above the CGL, providing additional limits and potentially dropping down to fill certain coverage gaps
• Additional Insured — additional insured endorsements on CGL are the most common contractual insurance requirement in commercial construction and leasing

How Brokers Use CGL in Practice

Every commercial lines account starts with a CGL limit analysis. The core questions: Is the per-occurrence limit adequate for the client's operations and contractual requirements? Is the general aggregate sufficient for their annual revenue and exposure? Does the client have professional service exposure that requires a separate E&O layer? Are there products/completed operations exposures requiring a separate aggregate? Is the client in a class that faces pollution, PFAS, or cyber exposures excluded from standard CGL forms? For brokers handling commercial accounts with significant professional services, technology, or contractor exposure, reviewing the interplay between the CGL exclusions and specialized coverage lines is essential to avoiding client coverage gaps.