QUEST DIAGNOSTICS Business Summary

Quest Diagnostics Inc. (DGX) operates as the global leader in diagnostic information services, generating the vast majority of its revenue through a fee-for-service model encompassing routine clinical testing, gene-based diagnostics, and esoteric pathology. The company’s operations are structured into two primary segments: Diagnostic Information Services (DIS), which accounts for approximately 96% of revenue via a massive network of patient service centers and rapid-response laboratories, and Diagnostic Solutions, which provides specialized clinical trials support and risk assessment services for life insurers. Quest leverages an unparalleled logistics infrastructure to serve roughly one-third of the adult U.S. population annually. Its primary direct competitors include Laboratory Corporation of America (Labcorp), Sonic Healthcare, and BioReference Health. Within this landscape, Quest maintains a dominant market position as part of a national duopoly with Labcorp, distinguished by its extensive proprietary clinical database and comprehensive payer contracts that provide a significant scale advantage over hospital-based and regional laboratories. Founded in 1967 by Paul A. Brown, MD, as Metropolitan Pathology Laboratory, the company evolved through its spin-off from Corning in 1996 into its current form. The leadership team is currently headed by James E. Davis, Chairman, CEO, and President, who joined the firm following a high-level executive tenure at GE Healthcare. The executive suite includes Sam Samad, Executive Vice President and CFO, who previously held the CFO role at Illumina, and Kristin Fellenz, Senior Vice President and Chief Information and Digital Officer, who leads the company’s digital transformation and data analytics strategy. The Board of Directors features prominent industry veterans such as Timothy M. Ring, former Chairman and CEO of C.R. Bard, and Vicky B. Gregg, former CEO of BlueCross BlueShield of Tennessee. The company’s ownership structure is dominated by major institutional investors, including The Vanguard Group, BlackRock, and State Street Corporation, reflecting its status as a foundational healthcare infrastructure asset.