Marsh McLennan Agency vs USI Insurance Services: How Do They Compare for Professional Liability (E&O) Insurance?

MMA names E&O with separate architects-and-engineers and lawyers professional lines. USI’s most detailed documented program is for CPAs: it covers third-party claims alleging professional services caused financial harm, with defense and covered damages. 3,7

What Is Marsh McLennan Agency?

Marsh McLennan Agency provides business insurance and employee health and benefits, alongside retirement, wealth, and private-client services across the United States and Canada. Its US small-business page lists six common coverage types and directs buyers to request a personalized quote by phone; the insurer and terms for a specific placement must be confirmed in the proposal. 1,2

Read the Marsh McLennan Agency profile

Read the Marsh McLennan Agency Professional Liability (E&O) Insurance page

What Is USI Insurance Services?

USI suits software and hardware companies from seed stage through IPO seeking consultative broker support; buyers wanting a self-serve quote should compare digital agencies. Insurer commissions are typical and contingent compensation may also apply. 4,5,6

Read the USI Insurance Services profile

Read the USI Insurance Services Professional Liability (E&O) Insurance page

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. 10,11,12,13

Read the full coverage guide

Key Differences in Professional Liability (E&O) Insurance

Which Professional Work Is Named

USI’s CPA program is underwritten by CNA and is marketed to sole practitioners and regional CPA firms; USI separately brokers E&O for other business types without naming a carrier in its general description. MMA’s overview does not identify the insurer for its placements, so buyers should compare the named carrier and eligible profession on each proposal. 3 7

Placement Scope and Buying Route

USI says CPA program firms receive claims support and risk resources such as engagement-letter templates, and directs quotes or renewals to USI Affinity. MMA invites organizations to contact an adviser or specialist; confirm whether the MMA proposal includes comparable profession-specific risk resources. 3 7

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

  • Does the USI AICPA program accept your firm type, and what claims and risk-management services accompany it? 7
  • Who underwrites the MMA quote, and what services are included for your profession? 3

Review Scores

These averages can combine ratings for different products, locations, and customer groups, including approximate BBB grade conversions. Read each review for the sources, scope, and calculation.

Marsh McLennan Agency

8.2/ 10

Review Score

2 rated sources

There are almost no public customer reviews of Marsh McLennan Agency (MMA). Trustpilot shows 3.2 out of 5, but from a single review, and BBB shows an A grade with four complaints closed in three years.[8][9][1]

Read Marsh McLennan Agency reviews

USI Insurance Services

6.4/ 10

Review Score

1 rated source

USI’s public feedback is too sparse and office-specific for a firmwide verdict. Check the local team’s responsiveness and experience with your type of business.[4][6][8]

Read USI Insurance Services reviews

Offering Details

Marsh McLennan Agency vs USI Insurance Services: Professional Liability (E&O) Insurance: documented features by provider

CriteriaMarsh McLennan Agency professional errors omissions (official overview)AICPA Professional Liability Program (USI Affinity)
Role in This Line

Marsh McLennan Agency describes arranging professional errors omissions for the audience stated on the cited product page. 3Company-reported. professional errors omissions marketed by marsh-mclennan-agency; scope is limited to the cited official product overview and described audience. This is not a policy form or a universal eligibility statement.

For CPA firms, USI runs the AICPA Professional Liability Program through its USI Affinity division as the endorsed producer, rather than underwriting the policy itself. USI's general Business Services practice separately brokers errors and omissions/professional liability coverage for other business types. 7,9Company-reported. AICPA program page and Business Services practice page.

Issuing Insurer

Confirm in your quote.

USI's own page states that the AICPA Professional Liability Program is "underwritten by CNA," naming the carrier for that specific program. USI's general Business Services E&O placements do not name an insurer. 7Company-reported. Direct quote from the AICPA program page; CNA underwrites only this named program, not USI's other professional-liability placements.

Who It’s For

Organizations seeking professional liability placement; source does not imply all professions share one policy. 3Company-reported. professional errors omissions marketed by marsh-mclennan-agency; scope is limited to the cited official product overview and described audience. This is not a policy form or a universal eligibility statement.

USI markets the AICPA program to sole practitioners and regional CPA firms. It has offered CPA coverage since 1967 and has been the endorsed AICPA Program provider since 1994. 7Company-reported. Program page description.

Coverage Features

The cited product page describes E&O and named specialist professional lines, including architects and engineers and lawyers professional liability; the overview does not treat them as one form. Marketing description only; actual coverage, exclusions, conditions, limits, and availability depend on the issued policy and jurisdiction. 3Company-reported. professional errors omissions marketed by marsh-mclennan-agency; scope is limited to the cited official product overview and described audience. This is not a policy form or a universal eligibility statement.

USI describes the policy as insuring a CPA and their practice against third-party claims that professional services caused financial harm, providing a defense and paying damages for covered claims arising from high-risk situations tied to new clients, changing business plans, or new laws and regulations. 7Company-reported. Program page description; actual insuring agreements, exclusions and conditions are set by the issued CNA policy form.

Limits and Retentions

The cited overview does not set a universal limit or retention for this line. Ask for the proposed policy form, limits, retentions, exclusions, and conditions in the quote. 3Not publicly disclosed. Only the cited marketing page was reviewed for published limit and retention information; no policy-form entitlement is inferred.

The AICPA program page does not publish limit, retention or premium figures; it says coverage plans allow a firm to tailor coverage to its risk profile. 7Not publicly disclosed. Page as read on 2026-09-23.

Risk Services

Confirm in your quote.

USI says firms enrolled in the program get supportive claims handling and exclusive access to risk-management resources, including engagement-letter templates, in addition to the coverage itself. 7Company-reported. Program page description.

How to Apply

The page invites organizations to contact a Marsh McLennan Agency adviser or specialist to discuss placement. The page does not establish a quote, bind, or coverage-effective timeline. 3Company-reported. professional errors omissions marketed by marsh-mclennan-agency; scope is limited to the cited official product overview and described audience. This is not a policy form or a universal eligibility statement.

USI directs CPA firms seeking a quote or renewal to contact USI Affinity, with a dedicated Affinity_APL@usi.com address for the AICPA program specifically. 7Company-reported. Contact instructions on the AICPA program page.

Full Comparison

More Marsh McLennan Agency vs USI Insurance Services Comparisons

Other Professional Liability (E&O) Insurance Comparisons

Sources

Marsh McLennan Agency

  1. Who We Are. Marsh McLennan Agency; Lines 193-195: ‘a business of Marsh’ and company-listed service lines across US and Canada. This does not establish the legal entity for an account, corporate ownership chart, or insurer role. Accessed 2026-09-29.
  2. Small Business Insurance Solutions. Marsh McLennan Agency; Lines 205-207: small-business audience and call invitation; lines 224-249 list six coverage categories and short descriptions; line 264 is an embedded form whose function is not stated. No form submitted. Accessed 2026-09-29.
  3. Executive and Professional Liability | MMA. Marsh McLennan Agency; E&O, architects and engineers, and lawyers professional lines are named in the policy suite. Accessed 2026-09-30.

USI Insurance Services

  1. The Power of ONE. USI Insurance Services; History, client-count, nationwide office, and P&C / benefits / personal risk / retirement description. Accessed 2026-09-16.
  2. Technology Insurance. USI Insurance Services; Technology practice client types, seed-to-IPO range, and listed insurance placement lines including PrivaSafe. Accessed 2026-09-16.
  3. Commissions and Fees. USI Insurance Services; Licensed-producer authority, insurer-paid commission default, contingent compensation, and client request right. Accessed 2026-09-16.
  4. Accountants Professional Liability — USI Affinity. USI Insurance Services; Quality Professional Liability Insurance Exclusively for CPA Firms; "The AICPA Professional Liability Program, underwritten by CNA, has been offering coverage to CPAs since 1967 and has been the endorsed provider of the AICPA Program since 1994."; supportive claims handling and exclusive access to extensive risk management resources, including engagement letter templates; Email Affinity_APL@usi.com. Accessed 2026-09-23.
  5. USI Specialty Program Solutions. USI Insurance Services; USI Affinity delivers high-quality insurance and financial solutions to members of affinity organizations and targeted industry segments...for professional associations, law firms, alumni and collegiate organizations, travel groups, and insurance administrators. Accessed 2026-09-23.
  6. Business Services. USI Insurance Services; USI advises clients...and provides solutions for...Errors & Omissions/Professional Liability... Accessed 2026-09-23.

Professional Liability (E&O) Insurance Guide

  1. 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.
  2. 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.
  3. Get business insurance. U.S. Small Business Administration; Six common types of business insurance table. Accessed 2026-09-16.
  4. 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.

Updated . 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. To suggest a correction, contact Spot with the page URL and supporting source.

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