Market Signals | Commercial Auto | Q3 2026

Market Signals | Commercial Auto | Q3 2026

Based on SERFF filings submitted between July 1 and August 24, 2026.

Executive Summary

Commercial Auto filing activity during Q3 2026 reflects a market balancing rate adequacy with product modernization. Across filings submitted this quarter, carriers are broadly adopting the ISO 2026 Commercial Auto form revisions, introducing new liability exclusions, recalibrating experience rating plans, filing significant rate changes in specialty transportation segments, and expanding Commercial Auto offerings through new proprietary endorsement suites.

While some developments represent broad market-wide adoption driven by ISO revisions, others reflect carrier-specific product strategies that may influence competitive positioning across specialty markets.

Key Market Insights

1.Broad ISO 2026 Multistate Form Revision Adoption (Market-Wide)

The ISO 2026 Commercial Auto Multistate Forms and Rules Revision package saw broad carrier adoption during Q3 2026. Across filings submitted this quarter, carriers adopted new Human Trafficking and Assault or Battery exclusions while updating War Exclusion language to explicitly address cyber means used in warlike action.

Harford Mutual Insurance Company adopted the revisions in South Carolina and Tennessee. Berkshire Hathaway Specialty Insurance Company filed phased adoption in South Dakota, while Columbia Insurance Company and National Liability & Fire Insurance Company adopted the revisions in Nebraska. Navigators Insurance Company filed a non-adoption in Mississippi, reflecting a state-specific implementation decision.

The ISO 2026 revisions are becoming the new baseline across Commercial Auto. Product, filing, and competitive intelligence teams should understand both the standard changes and where carriers are taking different approaches in specific states.

Filing details -

• HFMU-135031431

• HFMU-134965814

• BHSI-G134916483

• NAVG-135033321

• NAVG-135012964

• NTIN-134997789

2.Surge in New Exclusionary Endorsements: Assault & Battery, Loading/Unloading Sublimits, Excluded Entities (Transportation Specialty)

Beyond the ISO revisions, multiple filings this quarter introduced additional liability exclusions for transportation-related risks. These include proprietary Assault or Battery exclusions, Loading or Unloading Sublimits, and Excluded Entity endorsements.

RLI Insurance Company introduced mandatory Assault or Battery exclusions together with new transportation endorsements across Kentucky, Maine, and North Dakota. Westfield Insurance Group filed a proprietary Assault and Battery exclusion for Business Auto Coverage in North Carolina.

These filings illustrate how carriers writing transportation business are introducing additional coverage restrictions beyond the standard ISO forms.

Filing details -

• RLSC-135018502

• WSFG-G135012394

  
  

3.Specialty Segment Pricing: Rate Increases in Last-Mile Delivery (Old Republic)

Old Republic filed substantial Commercial Auto rate revisions for its Last Mile Delivery Program, including actuarial indications exceeding 80% for liability in Georgia. The filing attributes much of the increase to ISO loss cost revisions alongside company-specific loss experience.

Old Republic filed program revisions across Georgia, Nebraska, North Carolina, Delaware, Oregon, and several additional states. Vermont rejected the filing. 

Filing details -

• LDDX-134974800

• LDDX-134816677

• LDDX-134816741

  
  

4.Rate Activity Across Standard Business Auto: Modest Adjustments with UM/Medical Payments Pressure (Progressive)

Multiple carriers updated experience rating methodologies and expected loss ratios during Q3, reflecting continued refinement of Commercial Auto rating plans.

Acuity updated Commercial Auto Physical Damage Experience Rating credibility parameters in Pennsylvania and Kentucky. Church Mutual revised expected loss ratios and Commercial Auto Manual exception pages in Indiana, while BITCO adopted updated expected loss ratios aligned with ISO rating plans. 

Filing Details -

• ACUT-135008203

• ACUT-135018576

• CHMU-134882986

• LDDX-135019330

5.Auto Hacking / Cyber Risk Exclusions in Auto Dealers Coverage (Emerging Trend)

Commercial Auto filings are beginning to explicitly address cyber-related vehicle risks through new exclusionary language.

Markel introduced an Auto Hacking Incident and Security Event endorsement for Auto Dealers coverage in Idaho. Separately, the revised ISO War Exclusion extends exclusionary language to cyber means used in warlike action. 

Although currently concentrated within specialty business, these filings highlight an emerging direction in Commercial Auto coverage as connected vehicle risks continue to evolve.

Filing Details -

• MRKB-134945656

• NTIN-134997789

6.New Proprietary Endorsement Suite Launches (Product Expansion)

While many standard market filings focused on rate and coverage refinement, several specialty carriers expanded their Commercial Auto offerings through new proprietary endorsement suites.

Ascot introduced a multistate suite of endorsements including Additional Insured, Anti-Stacking, Earlier Notice of Cancellation, and Loss Payable forms across multiple states. Ascot also expanded insured definitions through a Massachusetts filing with Zurich American. 

These filings illustrate continued product development within the E&S and specialty Commercial Auto market despite broader rate correction across the industry.

Filing Details -

• GREY-G135020577

• ZURC-135027036

  
  

Notable Examples

Market Signals to Watch

Based on filings submitted through August 24, 2026, these are the market patterns worth monitoring in the coming months:

• Continued adoption of the ISO 2026 Commercial Auto Forms and Rules Revision package across additional carriers and states.

• Ongoing rate activity affecting last-mile delivery and specialty transportation business.

• Continued introduction of proprietary Assault or Battery exclusions within transportation products.

• Further recalibration of experience rating plans and expected loss ratios.

• Expansion of cyber-related exclusions beyond specialty Commercial Auto segments.

• Continued rollout of proprietary Commercial Auto endorsement suites by specialty carriers.

  
  

Summary 

Commercial Auto filings submitted during Q3 2026 reflect both broad market-wide developments driven by ISO revisions and carrier-specific product strategies responding to pricing pressure, transportation risks, and evolving coverage needs. Together, these filings provide an evidence-based view of how Commercial Auto products and rating approaches are changing across the market.

Go beyond the summary

This report highlights some of the most notable Commercial Auto filing trends from Q3 2026. With OverseeAI Research, you can dig deeper into the underlying filings, compare competitor products, and investigate the market questions most relevant to your businesswith source-backed answers.