<SEC-DOCUMENT>0000062709-18-000025-index.html : 20180629
<SEC-HEADER>0000062709-18-000025.hdr.sgml : 20180629
<ACCEPTANCE-DATETIME>20180629164645
ACCESSION NUMBER:		0000062709-18-000025
CONFORMED SUBMISSION TYPE:	11-K
PUBLIC DOCUMENT COUNT:		3
CONFORMED PERIOD OF REPORT:	20171231
FILED AS OF DATE:		20180629
DATE AS OF CHANGE:		20180629

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MARSH & MCLENNAN COMPANIES, INC.
		CENTRAL INDEX KEY:			0000062709
		STANDARD INDUSTRIAL CLASSIFICATION:	INSURANCE AGENTS BROKERS & SERVICES [6411]
		IRS NUMBER:				362668272
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		11-K
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-05998
		FILM NUMBER:		18929832

	BUSINESS ADDRESS:	
		STREET 1:		1166 AVENUE OF THE AMERICAS
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10036
		BUSINESS PHONE:		2123455000

	MAIL ADDRESS:	
		STREET 1:		1166 AVENUE OF THE AMERICAS
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10036

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	MARSH & MCLENNAN COMPANIES INC
		DATE OF NAME CHANGE:	19920703

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	MARLENNAN CORP
		DATE OF NAME CHANGE:	19760505
</SEC-HEADER>
<DOCUMENT>
<TYPE>11-K
<SEQUENCE>1
<FILENAME>mmcsip11k12312017.htm
<DESCRIPTION>MARSH & MCLENNAN COMPANIES 401(K) SAVINGS & INVESTMENT PLAN
<TEXT>
Document 1 - file: mmcsip11k12312017.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-23
<SEQUENCE>2
<FILENAME>mmc11k12312017exhibit23.htm
<DESCRIPTION>CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM
<TEXT>
Document 2 - file: mmc11k12312017exhibit23.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>3
<FILENAME>logommc2015.jpg
<DESCRIPTION>MMC LOGO
<TEXT>
Document 3 - file: logommc2015.jpg

</DOCUMENT>
</SEC-DOCUMENT>