internal
John Doyle
President & Chief Executive Officer
Corporate
4 yr
15 reports
Marsh & McLennan ·MMC
Four operating-company CEOs report directly to the group CEO
Financials · Fortune #175 · Divisional structure · 90K employees · New York, NY
9
CEO span
near peer avg (8)
2.8
Avg span
moderate
3
Max depth
3 levels
4.3 yr
Avg tenure
63%
Internal hires
↑ above industry avg
Interactive org chart
Marsh & McLennan organizational chart
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Four operating-company CEOs report directly to Marsh McLennan’s group CEO, an unusually pure divisional model. This page maps the leadership structure, executive team, and reporting lines across Marsh, Guy Carpenter, Mercer, and Oliver Wyman, with analysis and peer comparison.
What to model
Use the chart to test org decisions, not just view reporting lines
Start with the public baseline, then use the scenario views and source-backed changes to ask what happens when leadership, span, or team ownership shifts.
Latest signal Nick Studer joined as President & CEO, Oliver Wyman Group
Appointed July 2022 following prior leadership transition.
Source · See change logScenario views in the chart
- Add Chief AI Officer Create a group-level Chief AI Officer to coordinate data and AI strategy across all four operating companies.
- Add Group COO Introduce a Chief Operating Officer to reduce CEO span and centralize shared operations.
Atlas work this supports
- Connect Workday or UKG Get these analytics for YOUR org — tenure, span of control, headcount, automatically from your HRIS.
- Connect Salesforce Map your target accounts like this. Import contacts, visualize decision chains, plan multi-threading.
- Plan a Reorg Use this as a starting point. Model scenarios, compare structures, present options to your board.
The people
Who's running this
10 executives identified as Named Executive Officers in the most recent SEC proxy. Bar length scales with tenure.
internal
Martin South
President & CEO, Marsh
Marsh
4 yr
2 reports
internal
Martine Ferland
President & CEO, Mercer
Mercer
6 yr
1 reports
internal
Nick Studer
President & CEO, Oliver Wyman Group
Oliver Wyman Group
4 yr
1 reports
Mark McGivney
Chief Financial Officer
Finance
6 yr
2 reports
Open Role
Chief Information Officer
Technology
3 yr
0 reports
John Neal
President & CEO, Guy Carpenter
Guy Carpenter
5 yr
0 reports
Open Role
Chief People Officer
Human Resources
1 yr
0 reports
Open Role
Chief Legal & Compliance Officer
Legal
2 yr
0 reports
Open Role
Chief Marketing & Communications Officer
Marketing
2 yr
0 reports
The businesses
How Marsh & McLennan divides the work
4 divisions report into the group CEO. Tile size scales with estimated headcount.
Marsh
45K employees
President & CEO (Martin South)
Global insurance brokerage and risk advisory business serving commercial and institutional clients.
Guy Carpenter
6K employees
President & CEO (John Neal)
Global reinsurance intermediary specializing in treaty, facultative, and capital markets solutions.
Mercer
25K employees
President & CEO (Martine Ferland)
Human capital consulting across health, wealth, and career services.
Oliver Wyman Group
7K employees
President & CEO (Nick Studer)
Management consulting business focused on strategy, operations, risk, and transformation.
The thesis
Why this org is unusual
Four operating-company CEOs — Marsh, Guy Carpenter, Mercer, and Oliver Wyman Group — all report directly to the Marsh McLennan CEO.
This divisional design gives each business clear P&L ownership and preserves brand autonomy across risk, reinsurance, consulting, and human capital advisory.
The group center is relatively lean: finance, people, legal, technology, and communications functions support the divisions, but there is no standalone group COO layer. Compared with conglomerates that centralize operations, Marsh McLennan relies on experienced divisional CEOs to run day-to-day businesses, with the CEO coordinating strategy and capital allocation across them.
- No group COO
- Four operating-company CEOs
- High autonomy at division level
The comparison
How Marsh & McLennan stacks up
Peers such as Aon and WTW have moved toward more integrated operating models, consolidating advisory and brokerage leadership under fewer segment heads. Marsh McLennan stands out for maintaining four distinct operating-company CEOs with direct access to the group CEO. This structure increases CEO span of control but …
C-suite size
Marsh & McLennan
10
Aon
8
Willis Towers Watson
9
Accenture
10
McKinsey & Company
7
Reporting depth
Marsh & McLennan
3 levels
Aon
4 levels
Willis Towers Watson
4 levels
Accenture
5 levels
McKinsey & Company
4 levels
Avg C-suite tenure
Marsh & McLennan
4 yr
Aon
5 yr
Willis Towers Watson
4 yr
Accenture
6 yr
McKinsey & Company
5 yr
Has COO / Has CAIO
Marsh & McLennan — no COO — no CAIO
Aon — no COO — no CAIO
Willis Towers Watson ✓ COO — no CAIO
Accenture ✓ COO ✓ CAIO
McKinsey & Company — no COO — no CAIO
Current signals
What changed recently
Recent changes centered on appointing new CEOs at Marsh and Oliver Wyman, reinforcing the divisional leadership model.
Frequently Asked Questions
Who is the CEO of Marsh & McLennan?
John Doyle has served as President and CEO since 2022.
What type of organizational structure does Marsh & McLennan use?
Marsh McLennan uses a divisional structure built around four operating companies.
How many direct reports does Marsh & McLennan's CEO have?
The CEO has nine direct reports, including four operating-company CEOs and key corporate functions.
How has Marsh & McLennan's leadership changed recently?
The company appointed new CEOs at Marsh and Oliver Wyman in 2022, refreshing divisional leadership.
Who reports directly to Marsh & McLennan's CEO?
The CEOs of Marsh, Guy Carpenter, Mercer, and Oliver Wyman Group report directly to the group CEO.
Sources
- Company Newsroom, Jul 2022
- Company Newsroom, Jan 2022
- SEC EDGAR: Marsh & McLennan DEF 14A Proxy Statement
- SEC EDGAR: Marsh & McLennan 10-K Annual Report
Reference
Cite this page
If you reference this page in research, analysis, or news writing, use one of the formats below. Citation includes the SEC filing source where applicable.
APA 7th
Creately. (2026). Marsh & McLennan organizational structure. Creately. Retrieved , from https://creately.com/org-chart/fortune-500/marsh-and-mclennan/MLA 9th
"Marsh & McLennan Organizational Structure." Creately, April 1, 2026, https://creately.com/org-chart/fortune-500/marsh-and-mclennan/. Accessed .Chicago 17
Creately. "Marsh & McLennan Organizational Structure." Last modified April 1, 2026. https://creately.com/org-chart/fortune-500/marsh-and-mclennan/.Permanent URL: https://creately.com/org-chart/fortune-500/marsh-and-mclennan/ · last updated 2026-04-01