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

AIG offers customizable entity E&O to service providers; Marsh McLennan Agency describes professional liability placements and an application process for its target clients. 3,6

What Is AIG?

AIG is the marketing name for American International Group, Inc.; AIG says its insurance products are written or provided by subsidiaries or affiliates. Its U.S. business pages list commercial casualty, property, cyber, management and professional liability, and specialty programs, but a brand-level page does not identify the insurer for a particular policy. 1,2

Read the AIG profile

Read the AIG Professional Liability (E&O) Insurance page

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. 4,5

Read the Marsh McLennan Agency profile

Read the Marsh McLennan Agency 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. 7,8,9,10

Read the full coverage guide

Key Differences in Professional Liability (E&O) Insurance

Audience and Service Scope

AIG describes E&O for public and private service providers and can customize terms for their services. Marsh McLennan Agency documents a target audience for its professional-liability offering. Applicants should compare their actual work to that audience and ask each route to confirm coverage for all revenue-generating services, including subcontracted work. 3 6

Policy Placement

AIG markets the specialty entity policy, while Marsh McLennan Agency describes arranging coverage through its application process. A brokerage application brings the risk to insurers, but the quote and policy name the entity carrying the risk. Ask MMA which carriers it approached and compare the resulting form with AIG’s proposed wording. 3 6

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

  • Ask AIG for written confirmation of covered services, limits and issuing entity. 3
  • Ask Marsh McLennan Agency which insurer quoted and what information its application needs to assess every professional service. 6

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.

AIG

4.4/ 10

Review Score

2 rated sources

Customer ratings for AIG are low: Trustpilot shows 1.9 out of 5 from 252 reviews, and NerdWallet gives 2.5 stars and notes more claims complaints than expected. These pages cover many AIG products and countries, so they only loosely describe business insurance.[1][2]

Read AIG reviews

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

Offering Details

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

CriteriaAIG Specialty Professional Liability (E&O)Marsh McLennan Agency professional errors omissions (official overview)
Role in This Line

AIG markets customizable entity-based professional errors-and-omissions policies for public and private service providers. AIG is the marketing name; the page’s legal footer says products are written or provided by subsidiaries or affiliates, without naming the issuer for a buyer’s policy. 3Company-reported. AIG’s U.S. Professional Liability page. The page describes the marketed product family, not the legal insurer on an individual quote or policy.

Marsh McLennan Agency describes arranging professional errors omissions for the audience stated on the cited product page. 6Company-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.

Who It’s For

AIG says its specialty professional-liability offering is for service providers and can be customized for a company’s professional services. Its examples include public and private service providers; this does not state that every profession or applicant qualifies. 3Company-reported. Company-described target customer and customization statement. The reviewed page does not provide a complete class appetite or state availability list.

Organizations seeking professional liability placement; source does not imply all professions share one policy. 6Company-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.

Coverage Features

AIG describes coverage for claims alleging negligence in professional services rendered to others, including claims for third-party economic loss. This is a description of the product’s intended subject; covered claims, definitions, exclusions and conditions depend on the issued policy. 3Company-reported. AIG’s marketing description of specialty professional E&O; no policy form or endorsement was reviewed.

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. 6Company-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.

Limits and Retentions

The reviewed page does not state standard limits, retentions or deductibles for this offering. Confirm the amounts and policy conditions in the quote and issued form. 3Not publicly disclosed. AIG’s U.S. Professional Liability page reviewed 2026-09-30; no buyer-specific quote or policy was reviewed.

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. 6Not publicly disclosed. Only the cited marketing page was reviewed for published limit and retention information; no policy-form entitlement is inferred.

Risk Services

AIG says it uses in-house claims professionals and third-party experts, collaborates with clients through the claims process, and uses claims data to help clients evaluate and mitigate loss. These are company-reported service descriptions, not a claim outcome guarantee. 3Company-reported. General professional-liability claims services described by AIG. The page does not state account-specific service standards or identify the administrator for a particular policy.

Confirm in your quote.

How to Apply

Confirm in your quote.

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. 6Company-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.

Full Comparison

More AIG vs Marsh McLennan Agency Comparisons

Other Professional Liability (E&O) Insurance Comparisons

Sources

AIG

  1. Investor Relations. American International Group, Inc. (AIG); About AIG and legal footer; lines 244–246 and 327–331. Accessed 2026-09-28.
  2. Business. AIG US; Surplus Lines heading and paragraph, lines 357–359. Accessed 2026-09-28.
  3. Professional Liability Insurance. AIG US; ‘AIG Professional Liability Solutions,’ lines 327–334; claims expertise lines 273–279; broker contact lines 385–389; general policy-language caveat in legal footer lines 485–489. Accessed 2026-09-30.

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.

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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