Quest Diagnostics Incorporated is one of the largest clinical laboratory networks in the United States. Founded in New York in 1967 as Metropolitan Pathology Laboratory, the company spun off from Corning in 1996 and has grown through acquisitions into a Fortune 500 healthcare diagnostics provider. It runs a nationwide network of laboratories and patient service centers, offering tests that cover routine bloodwork, cancer screening, gene-based diagnostics, and drug testing. Quest employs approximately 50,500 people and generated $9.87 billion in revenue in 2024. The company trades on the New York Stock Exchange under the ticker DGX and is headquartered in Secaucus, New Jersey.
Key Stats
Quest Diagnostics History
Quest Diagnostics has gone through five decades of name changes, ownership shifts, and acquisitions. What started as a single pathology lab in New York grew into a national network after Corning Glass Works brought it under corporate ownership in 1982. The company took its current form and name after spinning off as an independent entity in 1996.
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1967Founded as Metropolitan Pathology Laboratory Paul A. Brown, MD, establishes the company in New York City to provide pathology testing services to hospitals and physicians.
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1969Renamed MetPath The company relocates to Teaneck, New Jersey and changes its name to MetPath, Inc., expanding its regional testing services.
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1982Acquired by Corning Glass Works Corning Glass Works acquires MetPath and renames it Corning Clinical Laboratories, folding it into its healthcare services division alongside pharmaceutical testing operations.
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1996Spun Off from Corning On December 31, Corning distributes shares of the renamed Quest Diagnostics Incorporated to its shareholders as an independent publicly traded company. Kenneth Freeman is appointed CEO.
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1999SmithKline Beecham Acquisition Quest acquires SmithKline Beecham Clinical Laboratories, nearly doubling its size and establishing it as the largest clinical laboratory company in the United States. GlaxoSmithKline retains a significant equity position post-deal.
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2003Unilab Acquired Quest acquires California-based Unilab Corporation for approximately $800 million, strengthening its position on the West Coast.
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2005LabOne Acquisition Quest pays approximately $934 million for LabOne, a Kansas-based risk assessment and clinical testing company that serves the life insurance industry — expanding Quest’s revenue beyond hospital-directed testing.
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2007AmeriPath Acquired Quest purchases AmeriPath, including its Specialty Laboratories subsidiary, from private equity firm Welsh Carson Anderson & Stowe. The deal establishes Quest as the leading provider of cancer diagnostic testing services in the country.
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2011Celera Acquisition Quest acquires Celera Corporation — the company that sequenced the human genome — adding advanced molecular diagnostics and proprietary genetic tests to its portfolio.
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2012New CEO Appointed Stephen Rusckowski, former CEO of Philips Healthcare, succeeds Surya Mohapatra as CEO. Rusckowski launches a multi-year strategy focused on revenue growth through health system partnerships, cost reductions, and diagnostic innovation.
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2020COVID-19 Testing at Scale Quest rapidly deploys COVID-19 PCR testing across its laboratory network, processing millions of tests monthly at peak demand. Revenue jumps to $9.44 billion, up from $7.73 billion the year before, as COVID testing volumes surge nationwide.
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2022Jim Davis Becomes CEO Jim Davis succeeds Stephen Rusckowski as Chairman, CEO, and President, continuing the company’s strategy of expanding through health system lab partnerships and advanced diagnostics.
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2024Revenue Recovery and M&A Push Revenue reaches $9.87 billion as base business volumes recover post-COVID. Quest completes multiple hospital laboratory acquisitions and expands its AD-Detect Alzheimer’s blood screening product line.
Quest Diagnostics Co-founders
Paul A. Brown, MD
Brown founded Metropolitan Pathology Laboratory in New York in 1967. A physician by training, he built the company from a single pathology practice into a multi-state clinical testing operation before Corning acquired it in 1982. The company’s current form and name came two decades after he established it.
Kenneth W. Freeman
Freeman was not a founder but is widely credited with shaping the modern Quest Diagnostics. Appointed CEO when the company spun off from Corning in 1996, he led the transformative SmithKline Beecham Clinical Laboratories acquisition in 1999, which made Quest the largest clinical lab operator in the US.
Quest Diagnostics Revenue
Quest Diagnostics held steady revenue between $7.49 billion and $7.73 billion from 2015 to 2019, reflecting the competitive pressure on clinical lab pricing and the transition away from its clinical trials testing business. COVID-19 testing drove a sharp two-year spike in 2020 and 2021. Revenue has since stabilised in the $9–10 billion range as the base diagnostic business has grown.
Quest Diagnostics Acquisitions
Quest Diagnostics has used acquisitions as the primary tool for expanding geographic reach, adding testing capabilities, and entering adjacent markets like risk assessment and molecular diagnostics. Most of its major deals occurred between 1999 and 2014, with a second wave of smaller hospital laboratory partnerships picking up pace in the 2020s.
The 1999 acquisition of SmithKline Beecham Clinical Laboratories was the most consequential deal in the company’s history. It cost roughly $1.3 billion and nearly doubled Quest’s laboratory network overnight. GlaxoSmithKline — which retained a significant equity stake after the deal — remained a major shareholder for several years.
The early 2000s brought three more large acquisitions. Quest paid $500 million for American Medical Laboratories in 2002, $800 million for California-based Unilab in 2003, and $934 million for LabOne in 2005. LabOne was notable because it added risk assessment services for the life insurance industry — a business line that today operates under the ExamOne brand.
In 2007, Quest acquired AmeriPath, a pathology services company with a focus on cancer diagnostics, and HemoCue, a Swedish maker of point-of-care hemoglobin testing devices. The same year it also picked up Specialty Laboratories, a California-based esoteric testing company that came bundled with the AmeriPath deal.
The 2011 acquisition of Celera Corporation brought in a portfolio of proprietary molecular tests and a gene-sequencing heritage. Celera had been part of the effort to sequence the human genome in the late 1990s. Its cardiovascular and pharmacogenomics tests remained commercially valuable to Quest for years after the acquisition.
More recent deals have concentrated on hospital laboratory management agreements and regional lab acquisitions. These tend to be smaller in dollar terms but strategically important — they extend Quest’s patient access network and generate recurring revenue from health systems that prefer to outsource their lab operations. The 2024 acquisition push included deals with hospital systems across multiple states as Quest pressed its case as the preferred outsourcing partner for health system labs.
Quest Diagnostics Market Cap
Quest Diagnostics has traded in a wide range over the past decade. Its market cap sat between $9 billion and $14 billion from 2015 to 2019 before the COVID-19 testing boom pushed it toward $22 billion in 2021. It has pulled back from those highs as COVID testing revenues faded, but remains above its pre-pandemic levels as the base business has grown.
Quest Diagnostics Competitors
Quest operates in a concentrated industry where Labcorp is its only direct national-scale competitor in the US commercial lab market. Beyond that head-to-head rivalry, Quest competes with hospital-based labs, regional independents, and diagnostic device makers. Becton Dickinson overlaps in point-of-care and rapid diagnostics, while companies like Sonic Healthcare challenge Quest in specific geographies and hospital outreach programs.
| # | Company | Country | Primary Segment |
|---|---|---|---|
| 1 | Labcorp | USA | Clinical Laboratory Testing |
| 2 | Sonic Healthcare | Australia | Clinical Laboratory Services |
| 3 | Eurofins Scientific | Luxembourg | Clinical & Environmental Testing |
| 4 | Becton Dickinson | USA | Diagnostics & Medical Devices |
| 5 | Abbott Laboratories | USA | Diagnostics & Medical Devices |
| 6 | Siemens Healthineers | Germany | Diagnostics & Imaging |
| 7 | bioMérieux | France | Microbiology & Infectious Disease |
| 8 | Hologic | USA | Women’s Health Diagnostics |
| 9 | OPKO Health | USA | Specialty Lab & Diagnostics |
| 10 | Myriad Genetics | USA | Genetic Testing |
FAQs
Who founded Quest Diagnostics?
Quest Diagnostics was founded by Paul A. Brown, MD, in 1967 as Metropolitan Pathology Laboratory in New York. The company was acquired by Corning in 1982 and spun off as Quest Diagnostics in 1996.
When did Quest Diagnostics become an independent company?
Quest Diagnostics became an independent publicly traded company on December 31, 1996, when Corning distributed its shares to shareholders. Kenneth Freeman was appointed CEO at the time of the spin-off.
What is Quest Diagnostics’ annual revenue?
Quest Diagnostics reported $9.87 billion in revenue for 2024, a 6.7% increase from 2023. Revenue peaked at approximately $10.79 billion in 2021 due to high COVID-19 testing volumes before declining as those volumes normalised.
Where is Quest Diagnostics headquartered?
Quest Diagnostics is headquartered at 500 Plaza Drive in Secaucus, New Jersey. The company is listed on the New York Stock Exchange under the ticker symbol DGX.
Who is Quest Diagnostics’ biggest competitor?
Labcorp (Laboratory Corporation of America) is Quest Diagnostics’ closest and largest competitor in the US clinical laboratory market. Both companies run nationwide laboratory networks and compete directly for physician, hospital, and health plan contracts.
