v3.26.3
Segment Information (Tables)
 9 Months Ended
Sep. 30, 2026
Segment Reporting [Abstract]  
Schedule of Selected Information and Details for MMC's Operating Segments
Selected information about the Company’s segments is as follows:
Three Months Ended September 30,

(In millions)		RevenueCompensation and benefitsDepreciation
and
amortization expense		Identified intangible
amortization expense		Other segment itemsOperating
Income
(Loss)
2026 –
Risk and Insurance Services$4,200 (a)$2,521 $50 $122 $762 $745 
Consulting2,685 (b)1,523 26 20 553 563 
Total Segments6,885 4,044 76 142 1,315 1,308 
Corporate/Eliminations(22)34 13 — 24 (93)
Total Consolidated$6,863 $4,078 $89 $142 $1,339 $1,215 
2025 –
Risk and Insurance Services$3,907 (a)$2,424 $52 $116 $565 $750 
Consulting2,465 (b)1,429 25 17 493 501 
Total Segments6,372 3,853 77 133 1,058 1,251 
Corporate/Eliminations(21)41 14 — 5 (81)
Total Consolidated$6,351 $3,894 $91 $133 $1,063$1,170 
Nine Months Ended September 30,

(In millions)
RevenueCompensation and benefitsDepreciation
and
amortization expense		Identified intangible
amortization expense		Other segment itemsOperating
Income
(Loss)
2026 –
Risk and Insurance Services$14,074 (c)$7,710 $151 $360 $2,319 $3,534 
Consulting7,845 (d)4,522 75 57 1,601 1,590 
Total Segments21,919 12,232 226 417 3,920 5,124 
Corporate/Eliminations(55)117 42 — 42 (256)
Total Consolidated$21,864 $12,349 $268 $417 $3,962 $4,868 
2025 –
Risk and Insurance Services$13,294 (c)$7,337 $153 $357 $1,641 $3,806 
Consulting7,150 (d)4,190 74 55 1,418 1,413 
Total Segments20,444 11,527 227 412 3,059 5,219 
Corporate/Eliminations(58)112 43 — 2 (215)
Total Consolidated$20,386 $11,639 $270 $412 $3,061 $5,004 
(a)Includes inter-segment revenue of $1 million in 2026, interest income on fiduciary funds of $100 million and $109 million in 2026 and 2025, respectively, and equity method income of $9 million and $5 million in 2026 and 2025, respectively. Revenue in 2026 includes a gain on the consolidation of Deasterra Partners, S.L., of $126 million.
(b)Includes inter-segment revenue of $22 million and $20 million in 2026 and 2025, respectively.
(c)Includes inter-segment revenue of $5 million in both 2026 and 2025, interest income on fiduciary funds of $273 million and $311 million in 2026 and 2025, respectively, and equity method income of $27 million and $20 million in 2026 and 2025, respectively. Revenue in 2026 includes a gain on the consolidation of Deasterra Partners, S.L., of $126 million. Revenue in 2025 also includes $28 million from a gain on the sale of the TCAS business and a gain on remeasurement of a previously held equity method investment to fair value upon consolidation.
(d)Includes inter-segment revenue of $51 million and $53 million in 2026 and 2025, respectively.
Schedule of Details of Operating Segment Revenue
Details of operating segment revenue are as follows:
Three Months Ended
 September 30,		Nine Months Ended
 September 30,
(In millions)2026202520262025
Risk and Insurance Services
Risk$3,796 $3,472 $11,709 $10,907 
Reinsurance404 435 2,365 2,387 
Total Risk and Insurance Services4,200 3,907 14,074 13,294 
Consulting
People and Investments1,672 1,579 4,931 4,573 
Management Consulting1,013 886 2,914 2,577 
Total Consulting2,685 2,465 7,845 7,150 
Total Segments6,885 6,372 21,919 20,444 
Corporate Eliminations(22)(21)(55)(58)
Total$6,863 $6,351 $21,864 $20,386