At-Bay vs 
Marsh Professional Liability (E&O) Insurance
Marsh names specialized industry practices for professional liability; At-Bay's MPL page publishes a $5 million limit ceiling instead.
What Is At-Bay Insurance?
At-Bay offers Cyber, Tech E&O, and miscellaneous professional liability insurance through its disclosed insurance agency and surplus lines broker. Its Stance security services have policy eligibility conditions, with managed detection and response sold separately. 1,2
What Is Marsh?
Marsh is a global insurance broker and risk advisor. In the United States it places coverage through core Marsh teams and through Marsh McLennan Agency for many middle-market buyers, including technology, cyber, property, casualty and benefits programs. 7,8,9,10
What Is Professional Errors and Omissions (E&O) Insurance?
Professional errors and omissions (E&O) insurance, also called professional liability insurance, addresses claims that professional services or advice caused a client financial loss. What's covered depends on the services actually scheduled in the policy, not the product label alone. 13,14,15,16
Key Differences in Professional Liability (E&O) Insurance
Named Industry Specialties Versus a General Appetite
Marsh names specialized industries its professional liability practice serves: banking and broker/dealers, insurance companies and asset managers, venture capital, accountants, attorneys, architects and engineers, media, technology, and healthcare and biotechnology. 11 At-Bay's MPL page instead describes eligibility in general terms, businesses of all revenue sizes, and points to a separate appetite guide for the specifics. 3
Named Specialist Staff Versus a Named Product Feature
Marsh says it employs attorneys, economists, and actuaries alongside coverage specialists to assess a client's professional-liability exposure given the complexity of these risks. 11 At-Bay does not describe comparable in-house specialist staff on its MPL page, focusing instead on listed policy features like the duty-to-defend contract and hammer clause. 3
What Neither Page Names
Marsh's reviewed pages do not name a specific professional liability insurer for a given placement. 11 At-Bay's current MPL page similarly does not name the insurer that would issue a new policy. 3
What to Confirm in Professional Liability (E&O) Insurance Quotes
- Ask Marsh which of its named industry specialties applies to your business and what that means for underwriting access. 11
- Ask At-Bay for its published $5 million limit ceiling and applicable state restrictions. 3
- Ask both companies to name the insurer that would actually issue your policy. 11 3
- Ask Marsh which specialists — attorneys, economists, or actuaries — would be involved in assessing your specific risk. 11
- Confirm whether At-Bay requires submission through a licensed insurance professional for your business. 3
Offering Details
At-Bay vs Marsh Professional Liability (E&O) Insurance: documented features by provider
| Criteria | At-Bay Miscellaneous Professional Liability (MPL) Insurance | Marsh Professional Liability Insurance Brokerage |
|---|---|---|
| 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. 3,4Company-reported. Current MPL product page and license disclosures; this describes the distribution channel, not who bears the underwriting risk. | Marsh's financial and professional liability practice places professional liability (errors and omissions) insurance; MMA also places E&O coverage within its executive and professional liability practice for middle-market clients. 11,12Company-reported. Marsh professional liability page and MMA executive and professional liability page. |
| 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. 3,5Not found in reviewed sources. 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. | The reviewed pages do not name a specific professional liability insurer. 11,12Not publicly disclosed. Marsh professional liability page and MMA executive and professional liability page as read on 2026-09-23. |
| 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. 3Company-reported. Current MPL appetite paragraph; the linked appetite guide's specific eligibility requirements were not independently opened for this record. | Marsh names specialized industries its professional liability experts serve, including banking and broker/dealers, insurance companies and asset managers, merchant banking and venture capital, accountants, attorneys, architects and engineers, media and entertainment, technology, and healthcare and biotechnology. 11Company-reported. Marsh professional liability page, What We Offer section. |
| 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. 3Company-reported. 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. | Marsh says professional liability coverage can protect a company against liability and defense costs from a claim alleging an error, omission or negligence in performing professional services, and that many policies also cover privacy violations and computer security breaches. 11Company-reported. Marsh professional liability page opening description; illustrative policy description, not a specific policy form. |
| 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. 3Company-reported. Current appetite paragraph; this is an advertised ceiling, not a guaranteed available limit for any specific applicant. | Not described in the reviewed sources. |
| Risk Services | Not described in the reviewed sources. | Marsh says it employs attorneys, economists and actuaries alongside coverage specialists to assess a client's professional liability exposure from multiple angles, given the complexity of these risks. 11Company-reported. Marsh professional liability page. |
| 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. 3,6Company-reported. Current submission instructions and the general broker-platform workflow description; MPL-specific automation details were not separately confirmed. | Not described in the reviewed sources. |
Full Comparison
More At-Bay vs Marsh Comparisons
Other Professional Liability (E&O) Insurance Comparisons
Sources
At-Bay
- Cyber, Tech E&O & Professional Liability Insurance. At-Bay; Product cards and agency disclosure. Accessed 2026-09-16.
- At-Bay Stance. At-Bay; Real Protection Against Real Threats; Endpoint, Email, MXDR; footnotes 1 and 3–6. Accessed 2026-09-16.
- MPL Insurance: Coverage Highlights & Appetite. 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.
- Licenses. At-Bay; Producer introduction; agency and surplus-lines footer naming At-Bay Insurance Services LLC. Accessed 2026-09-16.
- At-Bay Doubles Miscellaneous Professional Liability Appetite. At-Bay; September 28, 2023 release: final paragraph before Media Contacts. Accessed 2026-09-16.
- Broker Platform. At-Bay; How it works: Create a quote, Customize your quote, Bind your policy, Manage renewals; FAQs. Accessed 2026-09-16.
Marsh
- Marsh | Leader in risk, strategy, people, and investments. Marsh; Hero and capability tiles; FAQ: What does Marsh do?; industries served; Is Marsh the same as Marsh McLennan? January 2026 brand change. Accessed 2026-09-16.
- Compensation guide for US clients. Marsh; US broking segments; broker role; retail commissions, client fees, wholesale, insurer consulting, contingent and supplemental commissions; Marsh LLC and Marsh USA LLC; page 3: broker role and Marsh & McLennan Agency segment; page 7: copyright © 2024 Marsh LLC. Accessed 2026-09-16.
- Marsh McLennan Agency (MMA). Marsh; Middle-market US organizations; wholly-owned subsidiary; business insurance, employee health and benefits, retirement, private client. Accessed 2026-09-16.
- Technology | Insurance Broking & Risk Management. Marsh; Opening Technology Practice description; practice links including data center insurance, fintech and Stratus; Talk to us. Accessed 2026-09-16.
- Professional liability. Marsh; Opening description; What We Offer: specialized industries served (banking, insurance/asset managers, merchant banking/venture capital, accountants/attorneys/architects/engineers, media/communications/entertainment, technology, healthcare/biotechnology). Accessed 2026-09-23.
- Expert Executive and Professional Liability Insurance. Marsh McLennan Agency; Our policies include D&O, E&O, EPL, commercial crime/fidelity, network security privacy risk/cyber, fiduciary, media liability, IP, architects and engineers, lawyers professional, and kidnap and ransom. Accessed 2026-09-23.
Professional Liability (E&O) Insurance Guide
- FAQ: Professional liability insurance. 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.
- 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.
- Get business insurance. U.S. Small Business Administration; Six common types of business insurance table. Accessed 2026-09-16.
- Professional Liability – US Direct Errors and Omissions Insurance. 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.
