Occurrence vs Claims-Made: Which Policy Form Is Right for Your Business?

An occurrence policy covers incidents that happen during the policy period, regardless of when the claim is filed. A claims-made policy only covers claims reported while the policy is active (or during an extended reporting period). The choice permanently affects your long-term liability exposure and switching costs.

Who this is for: Business owners, contractors, and risk managers comparing professional liability, general liability, or medical malpractice coverage options and unsure which form protects them better.

TL;DR — Key Takeaways

• Occurrence = the injury or damage must happen during the policy year. You're covered even if sued five years later after the policy expires.
• Claims-made = the claim must be reported while the policy is in force (or within a tail period). Coverage vanishes if you let the policy lapse without buying a tail.
• Occurrence is usually preferred for general liability; claims-made is the industry standard for professional liability, E&O, D&O, and medical malpractice.
• Switching from claims-made to occurrence typically triggers a retroactive date gap — a period of potential uncovered exposure.
• Tail (extended reporting period) endorsements can cost 75%–200% of your annual premium depending on the carrier and profession.

What Is an Occurrence Policy?

An occurrence-based policy responds to any bodily injury or property damage event that occurs during the policy period — even if the claimant doesn't file until years later and your policy has already expired or been replaced.

Example: A contractor installs faulty wiring in March 2024. The wiring causes a fire in October 2027. If the contractor carried an occurrence policy in 2024, that policy still responds to the 2027 fire claim — even though the policy expired in 2024.

This "set-it-and-forget-it" protection is why occurrence is preferred by most commercial general liability (CGL) buyers. The Insurance Services Office (ISO) standard CGL form (CG 00 01) is an occurrence form by default.

What Is a Claims-Made Policy?

A claims-made policy requires two conditions to be met simultaneously:

1. The wrongful act or incident must have occurred on or after the policy's retroactive date (retro date).
2. The claim must be reported to the insurer while the policy is in force (or within an extended reporting period/ERP, if purchased).

Professional liability (E&O), directors & officers (D&O), employment practices liability (EPL), and medical malpractice policies are almost universally written on a claims-made basis because the long latency between a professional act and a lawsuit makes occurrence pricing actuarially difficult.

The Retroactive Date

The retroactive date is the earliest date from which prior acts are covered. If your retro date is January 1, 2022, a professional error you made in December 2021 would not be covered. Carriers often set the retro date to policy inception on new accounts, then keep it fixed at that original date at each renewal so earlier acts stay covered — coverage back to the first continuous policy is often called "full-prior-acts" coverage.

Occurrence vs Claims-Made: Side-by-Side Comparison

How Claims-Made Premium Matures Over Time

Unlike occurrence policies, claims-made premiums start low and rise each year as the policy's exposure base grows. Carriers refer to this as the policy "maturing" to full-limits pricing, typically reached at year 4 or 5. This matters when budgeting.

Illustrative maturation schedule (technology E&O, $1M/$2M limits):

Factors vary significantly by carrier, industry, and loss experience. Ask your broker for a multiyear projection.

How to Switch Between Policy Forms Without Creating a Gap

Changing policy forms or carriers is the most common source of accidental coverage gaps. Follow these steps:

1. Identify your current retro date. Pull your declarations page and note the retroactive date on your claims-made policy.
2. Request a tail quote from your existing carrier. Most carriers are contractually required to offer an ERP endorsement. Get pricing for 1-year, 3-year, and unlimited tails.
3. Request nose coverage (prior-acts coverage) from the new carrier. The new carrier matches your original retro date so no prior period is left uncovered.
4. Compare tail cost vs. nose cost. Buying a tail and starting fresh with a new retro date is sometimes cheaper than purchasing nose coverage — or vice versa. Run both scenarios.
5. Confirm the retro dates in writing before binding. Verify that the new policy's retro date matches the date you intended.
6. If switching to occurrence, ensure your current claims-made policy covers all open or potential claims before it expires. Buy a tail if in doubt.
7. Bind the new policy first, cancel the old policy second. Never let the claims-made policy lapse before the new policy is confirmed in force.

Real-World Scenario: Architect Switching Carriers Mid-Project

The setup: A small architectural firm in Texas carries professional liability (E&O) on a claims-made basis with a $1M per-claim / $2M aggregate limit. Retro date: January 1, 2020. Annual premium at year 5 (mature): $18,000.

The situation: A competing carrier offers a $14,000 premium on a new claims-made policy — but sets the retro date at January 1, 2025 (policy inception), not 2020.

The gap: Any claim arising from design work performed between January 2020 and December 2024 would be uncovered if the firm switches without addressing the prior-acts period.

The solution options:

This scenario is illustrative. Actual tail and nose pricing vary by carrier, claims history, and state. [Morrow to confirm carrier-specific availability in Texas.]

FAQ — Occurrence vs Claims-Made

1. Which is better: occurrence or claims-made?

Neither is universally better — it depends on the coverage line. For commercial general liability (slip-and-fall, property damage), occurrence is standard and preferred because coverage persists after the policy expires. For professional liability and E&O, claims-made is the industry norm, and occurrence forms are rarely available. The key is matching the right form to the exposure.

2. What happens if I cancel a claims-made policy without buying a tail?

Any claim reported after the policy cancellation date — even for incidents that happened while the policy was active — will be denied. This is one of the most common and costly mistakes small businesses make when switching insurers or closing up shop.

3. How long should my tail endorsement be?

For most professional liability exposures, a minimum 3-year tail is advisable given typical statutes of limitations for contract and negligence claims. Architects, engineers, and healthcare providers often need 5-year or unlimited tails because their projects have long latency periods and state-specific discovery rules can extend filing deadlines significantly.

4. What is a "nose" or prior-acts coverage?

Prior-acts coverage (sometimes called a "nose") is purchased from a new carrier to cover incidents that occurred before the new policy's inception date — back to an agreed retroactive date. It is an alternative to buying a tail from the old carrier.

5. Do occurrence CGL policies have a retroactive date?

No. Occurrence policies do not use a retroactive date mechanism. Coverage applies to any occurrence during the policy period regardless of when the claim is reported. This is a fundamental structural difference from claims-made forms.

6. Does my claims-made policy cover claims reported after I sell my business?

Only if you purchased a tail (ERP) or the acquiring company agrees to pick up prior-acts coverage under its policy. Business sales and M&A transactions are a common trigger for tail purchases. Failure to address this during a transaction can result in significant post-sale liability.

7. Can a general liability policy be written on a claims-made basis?

Yes, though it is uncommon. Some environmental liability, product liability, and pollution coverage is written claims-made. ISO does publish a claims-made CGL form (CG 00 02), but most standard market carriers use the occurrence form (CG 00 01). Surplus lines and specialty carriers may use claims-made CGL for higher-risk classes.

8. Is a claims-made policy cheaper than occurrence in the first year?

Yes, typically. A first-year claims-made policy is priced at roughly 50%–60% of the equivalent mature occurrence rate because the carrier's exposure window is narrow. The premium grows each year until it matures, usually by year 4 or 5.

Why Morrow for Occurrence vs Claims-Made Decisions

1. Independent access to multiple carriers and both policy forms. Morrow is an independent commercial P&C agency, not a captive agent. We can quote occurrence and claims-made options side by side across multiple admitted and surplus lines markets, so you see the real cost-benefit picture — not just one carrier's product.

2. Retroactive date audit at every renewal. Our producers review your retro date at every renewal and flag any gaps before they become a problem. We've caught retro date mismatches that would have left clients with years of uncovered professional liability exposure.

3. Tail and nose negotiation expertise. When clients switch carriers, retire, sell their business, or face a carrier non-renewal, Morrow negotiates tail pricing and coordinates nose coverage so no period falls through the cracks.

4. Claims advocacy when the trigger is disputed. Occurrence vs. claims-made disputes (e.g., "when did the wrongful act occur?") are a leading cause of coverage denials. Morrow advocates on your behalf with the insurer, including engaging coverage counsel when necessary.

5. Fast COI and certificate turnaround. Whether your contract requires evidence of claims-made coverage with a specific retro date or occurrence coverage with a completed-operations endorsement, Morrow turns around certificates of insurance the same business day in most cases. [Morrow to confirm current turnaround SLA.]

Get a Quote or Coverage Review

Ready to compare occurrence and claims-made options for your business?

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Morrow (Afthonea Inc, DBA Morrow) is a licensed commercial P&C insurance agency. [Morrow to confirm: licensed states, NPN, carrier appointments.] Coverage placed with admitted and surplus lines carriers rated A- (Excellent) or better by AM Best. Reviews: [Morrow to insert Google/Trustpilot rating and count.]

Related Pages

• Commercial Insurance Overview — the parent pillar covering all major lines
• Professional Liability (E&O) Insurance — the most common claims-made coverage line
• General Liability Insurance — standard occurrence-form CGL explained
• What Is a Retroactive Date? — glossary definition with examples
• Tail Coverage: Cost and When You Need It — deep dive on ERP endorsements
• D&O Insurance vs E&O Insurance — sibling comparison page

Author: Content reviewed by a licensed commercial P&C insurance producer with expertise in professional liability and specialty lines placements. Credentials on file with Morrow. Published: June 2026 Last updated: June 2026

Sources: - Insurance Services Office (ISO) — CGL forms CG 00 01 (occurrence) and CG 00 02 (claims-made) - National Association of Insurance Commissioners (NAIC) — policy form filing guidance - Insurance Information Institute (III) — "Claims-Made vs. Occurrence Policies" - State insurance department bulletins (general guidance; verify in your state) - AM Best — carrier financial strength ratings methodology