Written by Justin Goodman, CIC, CISC, CLCS, CEO and Co-Founder, Total CSR Published: August 26, 2026 · Last reviewed: August 26, 2026
In plain language: CG 00 01 is the base insurance form that spells out what a business’s general liability policy actually covers, including injuries to other people, damage to their property, and certain advertising-related claims. It sets the coverage grants, exclusions, and conditions that every endorsement on the policy builds around.
Technical definition: CG 00 01 is the ISO-drafted Commercial General Liability Coverage Form containing Coverage A (Bodily Injury and Property Damage), Coverage B (Personal and Advertising Injury), and Coverage C (Medical Payments). It defines occurrence-based coverage triggers, exclusions, conditions, and definitions that structure the entire CGL policy.
CG 00 01 at a Glance
| Attribute | Detail |
|---|---|
| Also known as | ISO CGL Coverage Form, Commercial General Liability Coverage Form |
| Category | Liability policy base form |
| Lines of business | Commercial General Liability |
| Industries most affected | Construction, manufacturing, retail, habitational, hospitality, professional services |
| Related forms or endorsements | CG 20 10 (Additional Insured – Ongoing Operations), CG 20 37 (Additional Insured – Completed Operations), CG 24 26 (Amendment of Insured Contract Definition), CG 21 06 (Exclusion – Access or Disclosure of Confidential Information) |
| Who bears the risk | Named insured and additional insureds scheduled by endorsement, subject to policy limits |
| Common solution | Endorsements attached to CG 00 01 to broaden, narrow, or clarify base coverage for specific exposures |
| Also interacts with | Umbrella and excess liability policies that follow form to CG 00 01, additional insured endorsements, contractual risk transfer agreements |
Key Takeaways
- CG 00 01 is the standardized ISO form that establishes the core bodily injury, property damage, and advertising injury coverage found in most commercial general liability policies.
- Agencies rely on CG 00 01 as the reference point for reviewing endorsements, exclusions, and additional insured requirements because nearly every CGL modification is measured against this base language.
- A common misunderstanding is assuming every carrier’s CGL policy uses identical language; some carriers use proprietary forms that mimic CG 00 01 but alter key definitions or exclusions.
- Agencies reduce errors and omissions exposure by always confirming whether a client’s policy is truly built on ISO CG 00 01 or a manuscript equivalent before making coverage representations.
What Is CG 00 01 in Insurance?
CG 00 01 is the Insurance Services Office’s standardized Commercial General Liability Coverage Form, and it functions as the foundation for the majority of CGL policies written in the United States. The form exists because before ISO standardized liability language in the 1980s, coverage terms varied so widely between carriers that comparing policies, litigating claims, and underwriting risk consistently was difficult. Standardization gives courts, adjusters, and agents a common reference point for interpreting coverage disputes.
The form is organized into three coverage parts. Coverage A addresses bodily injury and property damage liability arising from an occurrence. Coverage B addresses personal and advertising injury, covering offenses like libel, slander, and copyright infringement in advertisements. Coverage C provides limited medical payments regardless of fault, intended to resolve small injury claims quickly and avoid litigation.
A concrete example illustrates the mechanism. A landscaping company’s employee accidentally breaks a client’s sprinkler line while mowing, flooding a finished basement. The property damage claim falls under Coverage A of the CG 00 01 form attached to the landscaper’s CGL policy, triggering the insurer’s duty to investigate and potentially pay for the water damage, subject to the form’s exclusions and the policy’s limits.
Because CG 00 01 is the base, nearly every endorsement an agency attaches, from additional insured status to contractual liability amendments, is written to modify specific sections of this form rather than create coverage from scratch.
How Does CG 00 01 Work?
- The occurrence. An accident happens during the policy period that causes bodily injury or property damage to a third party, or an offense occurs that qualifies as personal and advertising injury under Coverage B.
- The claim or suit. The injured party or their attorney notifies the insured or files suit, and the insured reports the incident to their agent or carrier as required by the form’s conditions section.
- The coverage analysis. The carrier reviews the CG 00 01 form’s insuring agreement, exclusions, and any attached endorsements to determine whether the occurrence falls within Coverage A, B, or C and whether any exclusion applies.
- The defense and indemnity decision. The carrier accepts the claim under a reservation of rights, denies it, or agrees to defend and indemnify the insured up to the applicable limits shown on the declarations page.
- The resolution. The claim settles, goes to trial, or is denied, with the outcome shaped directly by how the base CG 00 01 language and any endorsements were drafted and applied.
Real Claim Examples Involving CG 00 01
Scaffolding fall on a general contractor’s site
A subcontractor’s worker fell from scaffolding on a commercial renovation project, suffering a back injury, and the injured worker’s attorney sued the general contractor for negligence. The general contractor’s CGL policy, built on CG 00 01, responded under Coverage A because the injury arose from an occurrence during ongoing operations. Because the subcontractor had named the general contractor as an additional insured via a CG 20 10 endorsement attached to the base form, the general contractor received a defense and indemnity from the subcontractor’s carrier as well, illustrating how endorsements layer onto CG 00 01’s core structure.
Defamation claim from a competitor’s advertisement
A regional HVAC company ran a radio ad comparing its pricing to a named competitor, and the competitor sued for disparagement and trade libel. The claim triggered Coverage B, Personal and Advertising Injury, within the CG 00 01 form rather than Coverage A, since no physical injury or property damage occurred. The carrier accepted the claim and provided defense counsel, demonstrating how Coverage B operates independently from the bodily injury and property damage sections most agents focus on first.
Completed operations claim years after project handoff
A roofing contractor completed a commercial installation, and two years later a leak caused significant water damage inside the building. The property owner sued the roofer, and the claim fell under the products-completed operations hazard defined within CG 00 01’s Coverage A section, which extends coverage beyond the moment work is finished. Because the roofer had let their CGL policy lapse and switched carriers without confirming completed operations coverage carried forward properly, the claim triggered a coverage gap dispute, underscoring why agencies must track completed operations exposure across policy renewals.
CG 00 01 vs. Claims-Made CGL Form: What Is the Difference?
CG 00 01 is the standard occurrence-based commercial general liability form, while the claims-made CGL form is an alternative ISO structure used for harder-to-place or long-tail exposures. The two forms determine coverage eligibility using fundamentally different triggers, which changes how agencies must handle renewals, tail coverage, and retroactive dates.
| Comparison area | CG 00 01 (Occurrence Form) | Claims-Made CGL Form |
|---|---|---|
| Primary use case | Standard commercial liability for most industries | Higher-hazard or specialty exposures where claims can emerge long after the policy period |
| Coverage / concept type | Triggered by when the occurrence happens, regardless of when the claim is filed | Triggered by when the claim is made, provided a retroactive date requirement is met |
| Typical exclusions | Expected or intended injury, contractual liability limits, pollution, professional services | Same base exclusions, plus retroactive date and prior acts considerations |
| Who is most affected by errors | Insureds who assume coverage applies to old occurrences without checking policy dates | Insureds who let claims-made coverage lapse without purchasing extended reporting period coverage |
| Common mistakes | Confusing occurrence coverage with automatic completed operations extension | Failing to secure tail coverage when switching carriers or canceling the policy |
What Are the Most Common Mistakes With CG 00 01?
- Assuming every carrier’s CGL policy is identical to CG 00 01 leads to coverage surprises, since many carriers file proprietary forms with narrower definitions or added exclusions that only resemble the ISO base form.
- Treating CG 00 01 as covering contractual liability automatically overlooks the form’s insured contract definition, which limits what indemnification obligations are actually covered absent a broadening endorsement.
- Failing to confirm which edition date of CG 00 01 is attached to a policy creates confusion during claims, since coverage language and exclusions have changed across ISO revisions.
- Overlooking the products-completed operations hazard language causes agencies to underestimate exposure for contractors and manufacturers whose products or work cause harm after project completion.
- Not reviewing how endorsements interact with CG 00 01’s base exclusions results in agents believing a client has broader coverage than the policy actually provides.
- Assuming Coverage B, Personal and Advertising Injury, covers professional errors leads to declined claims, since professional liability exposures are generally excluded and require a separate policy.
How to Explain CG 00 01 to a Client
Explaining CG 00 01 to a personal lines client
CG 00 01 is not something most personal lines clients will ever see directly, since it applies to businesses rather than homeowners or auto policies. If a client asks because they run a side business, explain that this form is the standard base for the liability policy protecting their business if someone gets hurt or their property gets damaged because of the client’s work.
Explaining CG 00 01 to a small business owner
CG 00 01 is the foundation of your general liability policy, and it is what determines whether an injury to a customer, damage to someone else’s property, or certain advertising claims against your business get covered. Think of it as the rulebook your insurance company follows when deciding whether to pay a claim, and any extra protections we add, like additional insured status for a landlord, get attached on top of this base form.
Explaining CG 00 01 to a CFO or risk manager
CG 00 01 is the ISO standard occurrence-based CGL form, and confirming your carrier uses this exact form, rather than a proprietary equivalent, matters for consistency across your program and any excess or umbrella layers that follow form. We should review the specific edition date and any manuscript endorsements attached, since deviations from standard language can materially affect how contractual liability, additional insured obligations, and completed operations exposures are treated in a loss scenario.
Frequently Asked Questions About CG 00 01
What does CG 00 01 actually stand for?
CG 00 01 is the ISO form number for the Commercial General Liability Coverage Form, where “CG” designates the commercial general liability line and “00 01” identifies this specific base form within ISO’s numbering system. It is not an acronym but a standardized form identifier used across the insurance industry.
Is CG 00 01 the same at every insurance company?
CG 00 01 is published by ISO and used broadly, but not every carrier attaches this exact form. Some carriers file their own proprietary CGL forms with similar structure but different exclusions or definitions, so agents should always confirm the actual form number on a policy rather than assuming ISO language applies.
Does CG 00 01 cover professional liability claims?
CG 00 01 generally excludes professional liability exposures, since Coverage A and B are built around bodily injury, property damage, and advertising-related offenses rather than errors in professional services. Businesses providing professional advice or services typically need a separate professional liability or errors and omissions policy alongside their CGL policy.
What is the difference between Coverage A, B, and C in CG 00 01?
Coverage A in CG 00 01 addresses bodily injury and property damage liability, Coverage B addresses personal and advertising injury such as libel or copyright infringement, and Coverage C provides limited no-fault medical payments for minor injuries. Each coverage part has its own insuring agreement and exclusions within the same form.
How does CG 00 01 interact with additional insured endorsements?
CG 00 01 provides the base coverage that additional insured endorsements, such as CG 20 10 or CG 20 37, extend to other parties like general contractors or landlords. The endorsement does not create new coverage on its own but modifies who qualifies as an insured under the existing CG 00 01 coverage grants.
Why do ISO forms like CG 00 01 get revised over time?
ISO revises CG 00 01 periodically to respond to emerging exposures, court interpretations, and industry feedback, which is why edition dates matter when comparing policies. An agency reviewing a client’s coverage should always check which edition of CG 00 01 is attached, since exclusions and definitions can shift materially between versions.
Related Insurance Terms
- Occurrence Form: A liability coverage structure, like CG 00 01, that triggers coverage based on when the injury or damage happened rather than when the claim was reported.
- Claims-Made Form: An alternative CGL structure that triggers coverage based on when a claim is filed, often requiring a retroactive date and potential tail coverage, contrasting directly with the occurrence trigger in CG 00 01.
- Additional Insured Endorsement: A policy modification attached to a base form like CG 00 01 that extends liability coverage to a party other than the named insured, commonly used in construction contracts.
- Products-Completed Operations Hazard: A coverage concept defined within CG 00 01’s Coverage A that extends liability protection to injuries or damage occurring after a product is sold or work is completed.
- Personal and Advertising Injury: The Coverage B section of CG 00 01 that addresses non-physical injury offenses like defamation, false arrest, and advertising-related copyright infringement.
- Insured Contract: A defined term within CG 00 01 that determines which contractual indemnification obligations are covered under the policy’s contractual liability provisions.
Sources and References
- International Risk Management Institute (IRMI). Commercial General Liability Coverage Form Overview.
- NAIC. Insurance Services Office (ISO) Overview.
About the Author
Justin Goodman, CIC, CCIP, CISC, CLCS, CRIS, PCIA, QCLS, MFHR CEO and Co-Founder, Total CSR, Inc.
Justin Goodman is a third-generation insurance broker with over two decades in agency operations. He has trained more than 50,000 CSRs, account managers, and producers in commercial and personal lines coverage, from workers’ compensation to construction risk. He was named 2024 Insurance Journal Agent of the Year and one of the nation’s top five construction insurance experts by Risk & Insurance. He is the author of Retain, which applies cognitive science research on memory and knowledge transfer to insurance training, and speaks nationally on how agencies build durable technical expertise in their teams.