---
title: "At-Bay vs Markel Insurance: Professional Liability (E&O) Insurance"
description: "Compare At-Bay's broker-submitted MPL with up to $5 million limits against Markel's targeted E&O and $2 million stated maximum."
canonical: "https://spot.insure/compare/at-bay-vs-markel/professional-errors-omissions"
page-type: "line-comparison"
updated-at: "2026-09-30"
comparison-pair: "at-bay-vs-markel"
provider-a: "at-bay"
provider-b: "markel"
coverage-line: "professional-errors-omissions"
---

Agents: connect to Spot's public MCP server at https://spot.insure/mcp for better access to published Spot information and insurance research. Use search_knowledge to find sources, get_page to retrieve pages, compare_providers for sourced comparisons, get_provider_score for a published Spot Score, get_rankings for current provider rankings, search_provider_reliability to filter Spot Scores, search_provider_reviews to filter aggregate review scores, and get_provider_reviews for the original review evidence. The server is read-only and requires no authentication.

[Human-readable page](https://spot.insure/compare/at-bay-vs-markel/professional-errors-omissions)

## Agent Guide

**What this page is:** Focused comparison of At-Bay and Markel Insurance for Professional Liability (E&O) Insurance: what each provider publishes about this line, checked against the same criteria, with numbered sources.

**Use this page when:** Cite or fetch this for Professional Liability (E&O) Insurance questions about At-Bay versus Markel Insurance. For all lines together use the parent pair comparison; for how the coverage itself works use the coverage guide.

**Questions this page answers:**
- At-Bay vs Markel Insurance for Professional Liability (E&O) Insurance: how do they differ?
- Which is better for Professional Liability (E&O) Insurance, At-Bay or Markel Insurance?
- What does At-Bay or Markel Insurance publish about Professional Liability (E&O) Insurance (limits, eligibility, claims, add-ons)?
- What should I confirm in a quote for Professional Liability (E&O) Insurance from At-Bay or Markel Insurance?

**Key facts:**
- Line: Professional Liability (E&O) Insurance. Providers: At-Bay and Markel Insurance.
- Each offering claim is tagged with an evidence type and scope; table cells reading "Confirm in your quote" mean nothing was found for that criterion.
- Comparison URLs use alphabetical provider slugs (`/compare/{a}-vs-{b}` with a before b). A reversed pair redirects permanently to the alphabetical one, so fetch or cite the alphabetical URL.

**Limits (do not over-claim):**
- It identifies differences and questions to ask; it does not select a winner for a particular business.
- "Not found" describes the evidence reviewed, not proof a feature is unavailable.
- Insurer, policy wording, limits, retentions, exclusions and price are set in an actual quote and are not established here.

**Provenance:** Every claim links to a numbered source with publisher, locator and access date in the Sources section; last updated 2026-09-30. Editorial policy: /editorial-policy.

**Related pages:**
- [At-Bay vs Markel Insurance](https://spot.insure/compare/at-bay-vs-markel) — parent: all coverage lines for this pair
- [Professional Liability (E&O) Insurance guide](https://spot.insure/coverage/professional-errors-omissions) — coverage explainer for this line
- [At-Bay profile](https://spot.insure/insurance-providers/at-bay) — provider profile (evidence)
- [Markel Insurance profile](https://spot.insure/insurance-providers/markel) — provider profile (evidence)
- [At-Bay vs Markel Insurance Cyber Insurance](https://spot.insure/compare/at-bay-vs-markel/cyber) — sibling comparison (other line, or other pair for this line)
- [AIG vs At-Bay Professional Liability (E&O) Insurance](https://spot.insure/compare/aig-vs-at-bay/professional-errors-omissions) — sibling comparison (other line, or other pair for this line)
- [AIG vs Markel Insurance Professional Liability (E&O) Insurance](https://spot.insure/compare/aig-vs-markel/professional-errors-omissions) — sibling comparison (other line, or other pair for this line)
- [Alliance Risk vs At-Bay Professional Liability (E&O) Insurance](https://spot.insure/compare/alliance-risk-vs-at-bay/professional-errors-omissions) — sibling comparison (other line, or other pair for this line)
- [Alliance Risk vs Markel Insurance Professional Liability (E&O) Insurance](https://spot.insure/compare/alliance-risk-vs-markel/professional-errors-omissions) — sibling comparison (other line, or other pair for this line)
- [Aon vs At-Bay Professional Liability (E&O) Insurance](https://spot.insure/compare/aon-vs-at-bay/professional-errors-omissions) — sibling comparison (other line, or other pair for this line)
- [Aon vs Markel Insurance Professional Liability (E&O) Insurance](https://spot.insure/compare/aon-vs-markel/professional-errors-omissions) — sibling comparison (other line, or other pair for this line)

# At-Bay vs Markel Insurance: How Do They Compare for Professional Liability (E&O) Insurance?

Compare At-Bay's broker-submitted MPL with up to $5 million limits against Markel's targeted E&O and $2 million stated maximum.

## Research Scope and Use

Use this comparison to evaluate At-Bay and Markel Insurance for Professional Liability (E&O) Insurance against the same documented criteria. It identifies differences and questions to confirm; it does not select a winner for a particular business. Offering claims are what each provider publishes about this line unless marked otherwise. “Not found” describes the evidence reviewed, not proof that a feature is unavailable. Confirm the insurer, policy wording, limits, retentions, exclusions and cost in an actual quote.

## Summary

At-Bay offers primary MPL to businesses of all revenue sizes up to $5 million through licensed professionals; Markel targets small businesses up to $5 million revenue and states a $2 million maximum. [3](https://www.at-bay.com/insurance/mpl/ "MPL Insurance: Coverage Highlights & Appetite") [9](https://www.markel.com/us/commercial/professional-and-management-liability/probiz "ProBiz | Professional Liability Coverage")

## What Is At-Bay Insurance?

At-Bay targets technology firms with up to $5 billion in revenue and offers cyber limits up to $10 million, plus technology E&O; buyers seeking a standard online business package should compare other carriers. Managed detection and response costs extra. [1](https://www.at-bay.com/insurance/ "Cyber, Tech E&O & Professional Liability Insurance") [2](https://www.at-bay.com/stance/ "At-Bay Stance")

[At-Bay profile](https://spot.insure/insurance-providers/at-bay)

## Markel Insurance: Specialty Business and Products

Markel Insurance is Markel Group's specialty and small-business insurance business, with offerings across packages, workers' compensation, cyber, professional and management liability, property, marine, and surety. Products use different insurers and distribution routes, so compare the issuer and terms shown on the specific quote. [7](https://www.markel.com/about-us "About us") [8](https://www.sec.gov/Archives/edgar/data/1096343/000109634326000020/mkl-20251231.htm "Markel Group Inc. 2025 Form 10-K")

[Markel Insurance profile](https://spot.insure/insurance-providers/markel)

## What Is Professional Errors and Omissions (E&O) Insurance?

Professional liability can help pay defense costs and covered losses when a client says your advice or service caused financial harm. If customers rely on your work, list every service you provide and check the claims-made reporting and prior-work terms. [10](https://www.tdi.texas.gov/commercial/pl-faq.html "FAQ: Professional liability insurance") [11](https://www.iii.org/article/professional-liability-insurance "Professional liability insurance") [12](https://www.sba.gov/counseling/launch-your-business/#business-insurance "Get business insurance") [13](https://www.hiscox.com/documents/pl-sample-policy-wording.pdf "Professional Liability – US Direct Errors and Omissions Insurance")

## Key Differences in Professional Liability (E&O) Insurance

### Published ceilings

At-Bay says it offers primary MPL to businesses of all revenue sizes, with limits up to $5 million, subject to state restrictions and eligibility. Markel's miscellaneous E&O page describes small businesses in selected industries, with a revenue scope up to $5 million and a stated $2 million maximum. A higher ceiling may matter when client contracts require larger limits, but confirm availability for your state and risk. [3](https://www.at-bay.com/insurance/mpl/ "MPL Insurance: Coverage Highlights & Appetite") [9](https://www.markel.com/us/commercial/professional-and-management-liability/probiz "ProBiz | Professional Liability Coverage")

### Form features and submission

At-Bay lists claims-made-and-reported cover, independent-contractor coverage, disciplinary-defense and a duty-to-defend contract; licensed professionals can submit by email or quote through its Broker Platform. Markel's reviewed description does not detail those features or an online broker workflow. Compare the actual defense wording and reporting rules, not just the headline limit. [3](https://www.at-bay.com/insurance/mpl/ "MPL Insurance: Coverage Highlights & Appetite") [6](https://www.at-bay.com/brokers/platform/ "Broker Platform") [9](https://www.markel.com/us/commercial/professional-and-management-liability/probiz "ProBiz | Professional Liability Coverage")


At-Bay also lists automatic coverage for acquired subsidiaries; Markel’s overview describes its small-business focus but does not address acquired-entity status. Ask both how a new subsidiary would be insured. [3](https://www.at-bay.com/insurance/mpl/ "MPL Insurance: Coverage Highlights & Appetite") [9](https://www.markel.com/us/commercial/professional-and-management-liability/probiz "ProBiz | Professional Liability Coverage")

## What to Confirm in Professional Liability (E&O) Insurance Quotes

- Ask At-Bay which states and appetite rules apply and whether your submission can reach the $5 million ceiling.
- Ask Markel for its reporting terms, independent-contractor treatment and available limit.

## Offering Details

| Criteria | At-Bay Miscellaneous Professional Liability (MPL) Insurance | Markel professional errors omissions (official overview) |
| --- | --- | --- |
| Role in This Line | At-Bay markets MPL as one of its own named insurance products, sold through its disclosed producer, At-Bay Insurance Services LLC, with the product page directed at "properly licensed insurance professionals" submitting business rather than at direct retail buyers. [3](https://www.at-bay.com/insurance/mpl/ "MPL Insurance: Coverage Highlights & Appetite") [4](https://www.at-bay.com/licenses/ "Licenses") (Evidence: Company-reported; scope: Current MPL product page and license disclosures; this describes the distribution channel, not who bears the underwriting risk..) | Markel describes offering professional errors omissions for the audience stated on the cited product page. [9](https://www.markel.com/us/commercial/professional-and-management-liability/probiz "ProBiz | Professional Liability Coverage") (Evidence: Company-reported; scope: professional errors omissions marketed by markel; scope is limited to the cited official product overview and described audience. This is not a policy form or a universal eligibility statement..) |
| Issuing Insurer | The current MPL product page does not name the insurer that issues the policy. A September 2023 press release named United Specialty Company in connection with MPL, but that historical reference does not establish the current issuing insurer for a new MPL quote. [3](https://www.at-bay.com/insurance/mpl/ "MPL Insurance: Coverage Highlights & Appetite") [5](https://www.at-bay.com/press_releases/at-bay-doubles-mpl/ "At-Bay Doubles Miscellaneous Professional Liability Appetite") (Evidence: Not found in reviewed sources; scope: Reviewed MPL page as of 2026-09-23 and the September 2023 press release; restates the existing provider fact that MPL's current issuer is unresolved, distinct from the August 2023 Cyber/Tech E&O transition to At-Bay Specialty Insurance Company paper..) | Confirm in your quote. |
| Who It’s For | At-Bay says it provides primary MPL for businesses of all revenue sizes with limits up to $5 million, subject to state restrictions and eligibility requirements detailed in a separate MPL appetite guide. [3](https://www.at-bay.com/insurance/mpl/ "MPL Insurance: Coverage Highlights & Appetite") (Evidence: Company-reported; scope: Current MPL appetite paragraph; the linked appetite guide's specific eligibility requirements were not independently opened for this record..) | Small businesses in ProBiz's targeted industries; source describes businesses up to $5 million revenue for the miscellaneous E&O product. [9](https://www.markel.com/us/commercial/professional-and-management-liability/probiz "ProBiz | Professional Liability Coverage") (Evidence: Company-reported; scope: professional errors omissions marketed by markel; scope is limited to the cited official product overview and described audience. This is not a policy form or a universal eligibility statement..) |
| Coverage Features | At-Bay lists MPL coverage highlights including automatic coverage for acquired subsidiaries, claims-made-and-reported coverage, coverage for independent contractors, disciplinary-proceedings defense, a duty-to-defend contract, personal-injury coverage (including emotional distress), punitive damages where insurable, a professional-services definition written for each insured, and an 80/20 hammer clause. [3](https://www.at-bay.com/insurance/mpl/ "MPL Insurance: Coverage Highlights & Appetite") (Evidence: Company-reported; scope: Product-page coverage-highlights list; an 80/20 hammer clause is a settlement provision where the insurer pays 80% and the insured pays 20% of costs after the insured declines a recommended settlement. The issued policy and declarations control actual wording, limits and exclusions..) | The cited product page describes miscellaneous E&O for covered claims arising from professional services, with the page describing separate E&O and management-liability products. Marketing description only; actual coverage, exclusions, conditions, limits, and availability depend on the issued policy and jurisdiction. [9](https://www.markel.com/us/commercial/professional-and-management-liability/probiz "ProBiz | Professional Liability Coverage") (Evidence: Company-reported; scope: professional errors omissions marketed by markel; scope is limited to the cited official product overview and described audience. This is not a policy form or a universal eligibility statement..) |
| Limits and Retentions | At-Bay publishes an MPL limit ceiling of up to $5 million, with state restrictions that are not detailed on the product page itself. [3](https://www.at-bay.com/insurance/mpl/ "MPL Insurance: Coverage Highlights & Appetite") (Evidence: Company-reported; scope: Current appetite paragraph; this is an advertised ceiling, not a guaranteed available limit for any specific applicant..) | For its miscellaneous E&O product, Markel states coverage up to $2 million; this is a product-page maximum, not a promise that every applicant or quote receives that amount. [9](https://www.markel.com/us/commercial/professional-and-management-liability/probiz "ProBiz | Professional Liability Coverage") (Evidence: Company-reported; scope: Markel ProBiz miscellaneous E&O marketing page; class, underwriting, policy terms, and actual quoted limit control..) |
| How to Apply | At-Bay directs MPL submissions to underwriting by email or through automatic quotes on its Broker Platform, which At-Bay describes as a workflow of creating a quote, customizing limits and retentions, and binding the policy. [3](https://www.at-bay.com/insurance/mpl/ "MPL Insurance: Coverage Highlights & Appetite") [6](https://www.at-bay.com/brokers/platform/ "Broker Platform") (Evidence: Company-reported; scope: Current submission instructions and the general broker-platform workflow description; MPL-specific automation details were not separately confirmed..) | The page invites prospective customers or brokers to contact Markel or the named underwriting team. The page does not establish a quote, bind, or coverage-effective timeline. [9](https://www.markel.com/us/commercial/professional-and-management-liability/probiz "ProBiz | Professional Liability Coverage") (Evidence: Company-reported; scope: professional errors omissions marketed by markel; scope is limited to the cited official product overview and described audience. This is not a policy form or a universal eligibility statement..) |

## Full Comparison

- [At-Bay vs Markel Insurance](https://spot.insure/compare/at-bay-vs-markel): all coverage lines, business roles, service and claims.
- [What Is Professional Errors and Omissions (E&O) Insurance?](https://spot.insure/coverage/professional-errors-omissions): Professional liability can help pay covered defense costs and losses when a client says your advice or service caused financial harm; check services and reporting terms.
- [At-Bay vs Markel Insurance Cyber Insurance](https://spot.insure/compare/at-bay-vs-markel/cyber)
- [AIG vs At-Bay Professional Liability (E&O) Insurance](https://spot.insure/compare/aig-vs-at-bay/professional-errors-omissions)
- [AIG vs Markel Insurance Professional Liability (E&O) Insurance](https://spot.insure/compare/aig-vs-markel/professional-errors-omissions)
- [Alliance Risk vs At-Bay Professional Liability (E&O) Insurance](https://spot.insure/compare/alliance-risk-vs-at-bay/professional-errors-omissions)
- [Alliance Risk vs Markel Insurance Professional Liability (E&O) Insurance](https://spot.insure/compare/alliance-risk-vs-markel/professional-errors-omissions)
- [Aon vs At-Bay Professional Liability (E&O) Insurance](https://spot.insure/compare/aon-vs-at-bay/professional-errors-omissions)
- [Aon vs Markel Insurance Professional Liability (E&O) Insurance](https://spot.insure/compare/aon-vs-markel/professional-errors-omissions)

## Sources

### At-Bay

1. [Cyber, Tech E&O & Professional Liability Insurance](https://www.at-bay.com/insurance/). At-Bay; Product cards and agency disclosure. Accessed 2026-09-16.
2. [At-Bay Stance](https://www.at-bay.com/stance/). At-Bay; Real Protection Against Real Threats; Endpoint, Email, MXDR; footnotes 1 and 3–6. Accessed 2026-09-16.
3. [MPL Insurance: Coverage Highlights & Appetite](https://www.at-bay.com/insurance/mpl/). At-Bay; MPL Coverage Highlights list; MPL Appetite paragraph; Send us your submissions; "material on this page is intended for use solely by properly licensed insurance professionals". Accessed 2026-09-23.
4. [Licenses](https://www.at-bay.com/licenses/). At-Bay; Producer introduction; agency and surplus-lines footer naming At-Bay Insurance Services LLC. Accessed 2026-09-16.
5. [At-Bay Doubles Miscellaneous Professional Liability Appetite](https://www.at-bay.com/press_releases/at-bay-doubles-mpl/). At-Bay; September 28, 2023 release: final paragraph before Media Contacts. Accessed 2026-09-16.
6. [Broker Platform](https://www.at-bay.com/brokers/platform/). At-Bay; How it works: Create a quote, Customize your quote, Bind your policy, Manage renewals; FAQs. Accessed 2026-09-16.

### Markel Insurance

7. [About us](https://www.markel.com/about-us). Markel; Markel at a glance; description of Markel Insurance within Markel Group Inc.. Accessed 2026-09-28.
8. [Markel Group Inc. 2025 Form 10-K](https://www.sec.gov/Archives/edgar/data/1096343/000109634326000020/mkl-20251231.htm). U.S. Securities and Exchange Commission; filed by Markel Group Inc.; Cover page; Part I, Item 1 Business—Markel Insurance, U.S. Wholesale and Specialty, Programs and Solutions; Part II, Item 7/8 for group and segment risks. Accessed 2026-09-28.
9. [ProBiz | Professional Liability Coverage](https://www.markel.com/us/commercial/professional-and-management-liability/probiz). Markel; Miscellaneous E&O; types of covered professional-service errors; ProBiz target classes and process.. Accessed 2026-09-30.

### Professional Liability (E&O) Insurance Guide

10. [FAQ: Professional liability insurance](https://www.tdi.texas.gov/commercial/pl-faq.html). Texas Department of Insurance; What’s professional liability coverage?; What types of damages…; What’s general liability insurance?; Do I need professional liability… if I have general liability…?; Is professional liability insurance required?; Can a client require…?; What’s the difference between occurrence policies and claims-made policies. Accessed 2026-09-16.
11. [Professional liability insurance](https://www.iii.org/article/professional-liability-insurance). Insurance Information Institute; Opening paragraphs (professional services/advice and E&O name); Claims not covered by general liability; What types of businesses need professional liability insurance?; What’s covered… and what’s not (claims-made versus occurrence, defense and judgments, non-financial/intentional limits, BOP/in-home exclusion). Accessed 2026-09-16.
12. [Get business insurance](https://www.sba.gov/counseling/launch-your-business/#business-insurance). U.S. Small Business Administration; Six common types of business insurance table. Accessed 2026-09-16.
13. [Professional Liability – US Direct Errors and Omissions Insurance](https://www.hiscox.com/documents/pl-sample-policy-wording.pdf). Hiscox Inc. specimen; About this Policy / Coverage for Claims Made Against You; I.A Insuring Agreement; I.B Defense; I.C Settlement; II.A Notice of Claims; II.C Optional Extended Reporting Period; III.A, III.K, III.M, III.R, III.S Exclusions; IV.A–B Limits and Deductible; VI.O Professional Services; VI.U Wrongful Act. Accessed 2026-09-16.

Updated 2026-09-30. Spot, a product of Tools for Enlightenment, publishes this research and works in the commercial insurance market. The comparison applies the same criteria to both providers. [Editorial policy](https://spot.insure/editorial-policy). To suggest a correction, [contact Spot](https://spot.insure/contact) with the page URL and supporting source.

## At-Bay Reviews

Review Score: 9.5 / 10 from 2 rated sources, equally weighted.

At-Bay’s public review evidence is thin: one old G2 review and a BBB complaint record. It is not enough to judge day-to-day service or claims handling.

- BBB: BBB rating A (A+ to F). At-Bay identity; US commercial insurance review/satisfaction evidence sought on BBB. Period: accessed 2026-09-25. Checked 2026-09-25. [At-Bay | BBB Business Profile](https://www.bbb.org/us/ca/mountain-view/profile/insurance-companies/at-bay-1216-1000025767)
- G2: G2 star rating 4.5 (5 stars); 1 reviews. At-Bay company/product feedback; G2 seller profile identifies its offering as cybersecurity insurance and lists San Francisco headquarters. Not an insurance-policy claims or commercial-buyer satisfaction study. Period: review dated 2020-09-21. Checked 2026-09-25. [At-Bay seller profile and reviews](https://www.g2.com/es/sellers/at-bay)

Reviewed 2026-09-25. [Read the sourced review](https://spot.insure/insurance-providers/at-bay/reviews).

## Markel Insurance Reviews

Review Score: 7.5 / 10 from 2 rated sources, equally weighted.

There is little public customer feedback on Markel. Trustpilot shows 2.5 out of 5 from just 5 reviews, and BBB lists 12 complaints closed in the last three years.

- J.D. Power: Commercial Lines Insurers agent satisfaction score 726 (out of 1,000). 2022 commercial-lines independent-agent satisfaction study and 2025 small-commercial customer study; these use different populations and measures Period: 2022. Checked 2026-09-29. [2025 U.S. Small Commercial Insurance Study](https://www.jdpower.com/business/press-releases/2025-us-small-commercial-insurance-study); [2022 U.S. Independent Agent Satisfaction Study](https://www.jdpower.com/sites/default/files/file/2022-10/2022134%20U.S.%20Independent%20Agent.pdf)
- Trustpilot: TrustScore 2.5 (out of 5); 5 reviews. Trustpilot brand-level page for markel.com. It mixes products and is not mapped to one legal insurer. Checked 2026-09-29. [Markel Reviews](https://www.trustpilot.com/review/markel.com)
- BBB: BBB business grade A+. BBB business profile for Markel Insurance Company headquarters/corporate-owned locations; review and complaint submissions may include other products and affiliates Checked 2026-09-29. [Markel Insurance Company Business Profile](https://www.bbb.org/us/va/glen-allen/profile/insurance-companies/markel-insurance-company-0603-4017547); [Markel Insurance Company Complaints](https://www.bbb.org/us/va/glen-allen/profile/insurance-companies/markel-insurance-company-0603-4017547/complaints)
- BBB: Complaints 12; 12 reviews. BBB profile for Markel Insurance Company; complaints may include other Markel products and affiliates and BBB says not all submissions are displayed. Period: last 3 years, as displayed 2026-09-29. Checked 2026-09-29. [Markel Insurance Company Complaints](https://www.bbb.org/us/va/glen-allen/profile/insurance-companies/markel-insurance-company-0603-4017547/complaints)

Reviewed 2026-09-29. [Read the sourced review](https://spot.insure/insurance-providers/markel/reviews).

## Agent and Developer Resources

- [Markdown page](https://spot.insure/compare/at-bay-vs-markel/professional-errors-omissions.md)
- [Developer resources](https://spot.insure/developers)
- [Public MCP server](https://spot.insure/mcp)
- [MCP server manifest](https://spot.insure/server.json)
- [OpenAPI description](https://spot.insure/openapi.json)
- [Public page index](https://spot.insure/llms.txt)