---
title: "At-Bay vs Liberty Mutual: Professional Liability (E&O) Insurance"
description: "Compare At-Bay’s published MPL limit ceiling with Liberty Mutual’s physician-focused professional-liability listing."
canonical: "https://spot.insure/compare/at-bay-vs-liberty-mutual/professional-errors-omissions"
page-type: "line-comparison"
updated-at: "2026-10-01"
comparison-pair: "at-bay-vs-liberty-mutual"
provider-a: "at-bay"
provider-b: "liberty-mutual"
coverage-line: "professional-errors-omissions"
---

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

## Agent Guide

**What this page is:** Focused comparison of At-Bay and Liberty Mutual 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 Liberty Mutual. 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 Liberty Mutual for Professional Liability (E&O) Insurance: how do they differ?
- Which is better for Professional Liability (E&O) Insurance, At-Bay or Liberty Mutual?
- What does At-Bay or Liberty Mutual 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 Liberty Mutual?

**Key facts:**
- Line: Professional Liability (E&O) Insurance. Providers: At-Bay and Liberty Mutual.
- 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 2026-10-01. Editorial policy: /editorial-policy.

**Related pages:**
- [At-Bay vs Liberty Mutual](https://spot.insure/compare/at-bay-vs-liberty-mutual) — 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)
- [Liberty Mutual profile](https://spot.insure/insurance-providers/liberty-mutual) — provider profile (evidence)
- [At-Bay vs Liberty Mutual Cyber Insurance](https://spot.insure/compare/at-bay-vs-liberty-mutual/cyber) — sibling comparison (other line, or other pair for this line)
- [At-Bay vs Liberty Mutual Tech E&O Insurance](https://spot.insure/compare/at-bay-vs-liberty-mutual/technology-errors-omissions) — 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 Liberty Mutual Professional Liability (E&O) Insurance](https://spot.insure/compare/aig-vs-liberty-mutual/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 Liberty Mutual Professional Liability (E&O) Insurance](https://spot.insure/compare/alliance-risk-vs-liberty-mutual/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 Liberty Mutual Professional Liability (E&O) Insurance](https://spot.insure/compare/aon-vs-liberty-mutual/professional-errors-omissions) — sibling comparison (other line, or other pair for this line)

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

Compare At-Bay’s published MPL limit ceiling with Liberty Mutual’s physician-focused professional-liability listing.

## How to Use the At-Bay vs Liberty Mutual Professional Liability (E&O) Insurance Comparison

Use this comparison to evaluate At-Bay and Liberty Mutual 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.

## At-Bay vs Liberty Mutual Professional Liability (E&O) Insurance Summary

At-Bay publishes MPL limits up to $5 million for eligible businesses; Liberty Mutual lists a Physicians & Surgeons Professional liability-only program without published limits. [3](https://www.at-bay.com/insurance/mpl/ "MPL Insurance: Coverage Highlights & Appetite") [9](https://business.libertymutual.com/commercial-solutions/programs/ "Programs")

## 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)

## What Is Liberty Mutual Business Insurance?

Liberty Mutual spans small-commercial, commercial, specialty, surety, and reinsurance businesses. The insurer and distribution route depend on the product, so check the offer and policy before you compare terms. [7](https://www.libertymutualgroup.com/about-lm/investor-relations/our-company/company-profile "Company Profile") [8](https://business.libertymutual.com/commercial-solutions/ "Commercial Insurance Solutions")

[Liberty Mutual profile](https://spot.insure/insurance-providers/liberty-mutual)

## 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")

## What Are the Key Differences Between At-Bay and Liberty Mutual Professional Liability (E&O) Insurance?

### Limit and eligibility detail

At-Bay says it offers primary miscellaneous professional liability for businesses of all revenue sizes, with limits up to $5 million subject to state restrictions and eligibility. Liberty Mutual lists a Physicians & Surgeons Professional program as “PL Only,” but its listing does not state limits or detailed form terms. The available public figures let an eligible At-Bay applicant begin limit discussions; a Liberty Mutual quote is needed to establish the offered amount. Neither headline establishes approval or a particular retention. [3](https://www.at-bay.com/insurance/mpl/ "MPL Insurance: Coverage Highlights & Appetite") [9](https://business.libertymutual.com/commercial-solutions/programs/ "Programs")

### Submission channel and coverage wording

At-Bay directs licensed insurance professionals to submit by email or through its Broker Platform, where they can quote, customize limits and retentions, and bind. [6](https://www.at-bay.com/brokers/platform/ "Broker Platform") Liberty Mutual says its specialty programs are managed by program administrators and gives inquiry contacts. These are distinct application paths, and the label “professional liability” does not reveal matching coverage triggers. Buyers should compare definitions, defense provisions and state availability in issued forms. [3](https://www.at-bay.com/insurance/mpl/ "MPL Insurance: Coverage Highlights & Appetite") [9](https://business.libertymutual.com/commercial-solutions/programs/ "Programs")

## What Should You Confirm in At-Bay and Liberty Mutual Professional Liability (E&O) Insurance Quotes?

- Ask At-Bay whether your state and profession qualify and confirm available limits, retention and professional-services definition.
- Ask Liberty Mutual’s administrator for the program’s insurer, limit options, application steps and form wording.

## At-Bay vs Liberty Mutual Professional Liability (E&O) Compared

| Criteria | At-Bay Miscellaneous Professional Liability (MPL) Insurance | Physicians & Surgeons Professional program |
| --- | --- | --- |
| 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..) | Liberty Mutual lists a Physicians & Surgeons Professional program, marked “PL Only,” in its specialty-program portfolio. [9](https://business.libertymutual.com/commercial-solutions/programs/ "Programs") (Evidence: Company-reported; scope: Official Liberty Mutual commercial/product page; company-reported description scoped to Physicians & Surgeons Professional program. Not policy wording, underwriting approval, state eligibility or a coverage guarantee..) |
| 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..) | Liberty Mutual says its programs are managed by program administrators; the page provides program inquiry contact details. [9](https://business.libertymutual.com/commercial-solutions/programs/ "Programs") (Evidence: Company-reported; scope: Official Liberty Mutual commercial/product page; company-reported description scoped to Physicians & Surgeons Professional program. Not policy wording, underwriting approval, state eligibility or a coverage guarantee..) |
| 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 listing identifies professional liability only; it does not establish form terms, limits, exclusions or insurer for a quote. [9](https://business.libertymutual.com/commercial-solutions/programs/ "Programs") (Evidence: Company-reported; scope: Official Liberty Mutual commercial/product page; company-reported description scoped to Physicians & Surgeons Professional program. Not policy wording, underwriting approval, state eligibility or a coverage guarantee..) |
| 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..) | Confirm in your quote. |
| 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 cited product page does not establish an online application or policy-binding path; ask the listed team or your broker/agent how this product is placed. [9](https://business.libertymutual.com/commercial-solutions/programs/ "Programs") (Evidence: Not found in reviewed sources; scope: Reviewed product-page scope only. This not-found disposition is not a claim that no digital route exists..) |

## Related Pages for At-Bay vs Liberty Mutual

- [At-Bay vs Liberty Mutual](https://spot.insure/compare/at-bay-vs-liberty-mutual): 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 Liberty Mutual Cyber Insurance](https://spot.insure/compare/at-bay-vs-liberty-mutual/cyber)
- [At-Bay vs Liberty Mutual Tech E&O Insurance](https://spot.insure/compare/at-bay-vs-liberty-mutual/technology-errors-omissions)
- [AIG vs At-Bay Professional Liability (E&O) Insurance](https://spot.insure/compare/aig-vs-at-bay/professional-errors-omissions)
- [AIG vs Liberty Mutual Professional Liability (E&O) Insurance](https://spot.insure/compare/aig-vs-liberty-mutual/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 Liberty Mutual Professional Liability (E&O) Insurance](https://spot.insure/compare/alliance-risk-vs-liberty-mutual/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 Liberty Mutual Professional Liability (E&O) Insurance](https://spot.insure/compare/aon-vs-liberty-mutual/professional-errors-omissions)

## Sources for At-Bay vs Liberty Mutual

### Sources About 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.

### Sources About Liberty Mutual

7. [Company Profile](https://www.libertymutualgroup.com/about-lm/investor-relations/our-company/company-profile). Liberty Mutual Group; Strategic business units paragraph: US Retail Markets (individuals/small businesses; small commercial; countrywide) and Global Risk Solutions (mid-size/large businesses; commercial, specialty, reinsurance, surety; worldwide).. Accessed 2026-09-29.
8. [Commercial Insurance Solutions](https://business.libertymutual.com/commercial-solutions/). Liberty Mutual Business Insurance; Commercial solutions index names commercial auto and fleet, cyber, environmental liability, equipment breakdown, excess and surplus, general liability, healthcare liability, inland marine, management liability, multinational, ocean marine, professional liability, property, reinsurance, surety, umbrella/excess and workers compensation. Disclosure says policy insurer is named when offered, may be an affiliate/subsidiary or surplus-lines insurer; states/jurisdictions and actual policy terms vary.. Accessed 2026-09-29.
9. [Programs](https://business.libertymutual.com/commercial-solutions/programs/). Liberty Mutual Business Insurance; ‘Our programs portfolio’ lists Auto Salvage/Dismantlers, Fire Suppression and Sprinkler Contractors, Nonprofits, Physicians & Surgeons Professional (PL only), Post-surgical for bariatric and plastic surgeries, Roofing Contractors, Scrap Metal Dealers, Self-storage, and Sports and Fitness. Page says programs are managed by program administrators; not a complete business catalogue.. Accessed 2026-09-29.

### Sources for the 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 2026-10-01. 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 Review Scores for 2026

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).

## Liberty Mutual Review Scores for 2026

Review Score: 7.2 / 10 from 2 rated sources, equally weighted.

Customers give Liberty Mutual 4.2 out of 5 on Trustpilot from 3,836 reviews, but that page mixes auto, home and life customers with business ones. For business insurance specifically, NerdWallet gives 3.0 out of 5 and reports more complaints than expected.

- NerdWallet: NerdWallet editorial rating 3.0/5 (NerdWallet proprietary editorial score; not a consumer rating average or Spot Score). NerdWallet business-insurance editorial review, updated June 3, 2026. Its 3.0/5 is NerdWallet’s editorial score, not a consumer average or Spot Rating. It reports above-expected commercial-property and general-liability complaints for 2022–2024 and a low J.D. Power result. Period: Page updated June 3, 2026. Checked 2026-09-29. [Liberty Mutual Business Insurance Review 2026: Big Company Dogged by Customer Complaints](https://www.nerdwallet.com/business/insurance/learn/liberty-mutual-business-insurance)
- Trustpilot: Trustpilot consumer TrustScore 4.2/5 (Platform aggregate for a mixed Liberty Mutual brand profile; not business-only); 3836 reviews. Company-wide Liberty Mutual Trustpilot profile. Its description highlights auto, home and life insurance; review excerpts are not restricted to commercial buyers or one issuing entity. The displayed score/count are a consumer-review-site aggregate, separate from editorial ratings and survey data. Period: Displayed September 29, 2026; live total changes. Checked 2026-09-29. [Liberty Mutual Reviews](https://www.trustpilot.com/review/www.libertymutual.com)

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

## Agent and Developer Resources

- [Markdown page](https://spot.insure/compare/at-bay-vs-liberty-mutual/professional-errors-omissions.md)
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