Aon vs Marsh McLennan Agency: How Do They Compare for Business Insurance?

Aon’s U.S. Commercial Risk terms describe Commercial Risk Solutions U.S. as broker of record for certain insurance programs. Separate electronic-delivery terms name Aon Risk Services Companies, Inc. acting for itself and licensed brokerage subsidiaries to deliver arranged policies; the terms define an insurer as the policy issuer and risk bearer. These group-level descriptions do not identify the producer or authority for a particular placement. ^1,2Company-reportedCompany-reported U.S. Commercial Risk brokerage and electronic-delivery terms; certain programs only. No specific insured, licensed producer, appointment, policy issuer, state authority or placement was matched.

As of 2026-09-28, Marsh’s US legal-entity page lists Marsh & McLennan Agency LLC as the current entity name for Marsh Agency (formerly MMA) and Marsh Agency LLC as proposed, with displayed state completion statuses marked TBD. Louisiana’s regulator lists Marsh & McLennan Agency LLC as a producer agency with active casualty, accident and health or sickness, life, property, and surplus-lines authorities through 2028-03-31. This is Louisiana-specific producer evidence, not evidence of an insurer role or nationwide licensing. ^24,15VerifiedCurrent entity name and proposed legal-name transition as listed on Marsh’s US legal-entity page, plus producer-authority evidence for Louisiana only, accessed 2026-09-28. No other state licensing was audited; this record does not establish an insurer or underwriting role.

Marsh McLennan Agency describes itself as a business of Marsh and lists business insurance, employee health and benefits, retirement and wealth, and private-client insurance services across the United States and Canada. ¹⁶Company-reportedCurrent MMA company description. Does not establish corporate ownership structure, the legal entity for a particular placement, or an insurer role.

Aon markets a dedicated Middle Market practice for mid-sized organizations and says it serves growing businesses across North America. The reviewed page gives no numerical size cutoff and does not establish U.S.-only eligibility; Aon’s broader global client statement describes the parent’s client base, not this practice’s eligibility rules. ^4,3Company-reportedCompany-reported marketing page, North America; no numerical revenue, employee-count, state or U.S.-only eligibility definition is stated.

MMA describes Marsh Agency as a separate business unit serving as an advocate and broker for the middle market. ²⁷Company-reportedCompany-stated role and customer focus for the future Marsh Agency operating brand; not a revenue, size, or eligibility threshold.

MMA’s US industry directory includes pages for construction, financial institutions, healthcare, manufacturing, real estate, and transportation and trucking. These are examples of stated sector focus, not a complete appetite or eligibility list. ²²Company-reportedExamples from MMA’s national US industry directory; the directory is evidence of stated sector focus, not a complete appetite or eligibility list.

For certain U.S. Commercial Risk programs, Aon says it consults with the client about market conditions, insurers to approach and program strategy, helps prepare underwriting information and applications, and obtains the client’s instructions to bind specific programs based on Aon’s proposal. The client signs applications that require a signature. ¹Company-reportedCompany-reported contractual terms for certain U.S. Commercial Risk programs; not a universal workflow, online checkout claim, insurer role or guarantee that a quote can bind.

MMA’s US small-business page lists general liability, commercial property, workers’ compensation, professional liability, commercial auto, and cyber liability, and invites buyers to call 833-256-4266 for a personalized quote. The page also contains a small-business specialist form, but its function and any online application, purchase, or binding route are not established by the page reviewed. ²⁹Company-reportedUS small-business landing page only. The phone invitation does not establish quote speed, eligibility, online purchase or binding; the embedded specialist form's function was not established.

Aon says it consults with clients before placing or renewing coverage and, where applicable, administers the insurer relationship for selected programs, including billing, data reporting and negotiated requirements. The terms do not promise automatic renewal, a timetable, a specific market or a particular outcome. ¹Company-reportedCompany-reported terms for selected U.S. Commercial Risk programs; administration varies where applicable and may be changed by written agreement.

MMA says the Marsh Agency brand transition will not change clients’ account manager, team, or point of contact, and will not affect existing policies or programs; clients may see the legal-name change during renewals. This describes the rebrand transition, not MMA’s general renewal process. ²⁷Company-reportedOnly the announced Marsh Agency rebrand and its stated effect on existing clients; this does not document MMA’s general renewal workflow, renewal service level, or policy terms.

MMA’s Tampa office page lists InsurLink for policy and endorsement access, CSR24 for certificates, carrier contact information for commercial and personal-lines claims, and a local-consultant contact route. ³¹Company-reportedServices and client tools listed on the Tampa, Florida office page only. The claims listing provides carrier contact information and does not establish that MMA adjusts claims.

Under Aon’s U.S. brokerage terms, the client is responsible for directly notifying insurers as its policies require unless a separate signed agreement says otherwise; Aon says it does not assume that notice or monitoring duty without a separate written agreement. This allocation does not determine whether Aon separately offers or agrees to claims advocacy or other claims-related services. ^1,5,7Company-reportedCompany-reported contractual allocation for covered U.S. Commercial Risk services; policy terms and any separate written agreement control. Aon separately describes claims advocacy on its D&O and cyber pages.

On its business-interruption page, MMA says it will advocate with insurers for clients if complex claim issues arise. This is a company-reported service statement; it does not establish claim outcomes or an adjusting/payment role. ¹⁷Company-reportedCompany-described support for complex claims in the business-income and contingent-business-interruption page context; not a promise of claim outcomes or evidence that MMA adjusts or pays claims.