McKesson Corporation

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Lore & Background

McKesson was founded in 1828 in New York City as Charles M. Olcott by Charles M. Olcott. It was later renamed Olcott, McKesson & Co. and John McKesson in 1833. The business began as an importer and wholesaler of botanical drugs. A third partner, Daniel Robbins, joined as the enterprise grew, and the company was renamed McKesson & Robbins following Olcott's death in 1853. In 1938, the company was involved in the McKesson and Robbins scandal under CEO Phillip Musica, one of the most notorious business and accounting scandals of the 20th century, which led to major changes in American auditing standards and securities regulations after being exposed in 1938. It was found that one fourth of the $86,556,270 assets of the company was just figures recorded to keep McKesson looking profitable while Musica, who was posing as F. Donald Coster, and his brothers stole the funds. The company weathered the crisis through an equity receivership. In 1967, Foremost Dairies acquired McKesson & Robbins in a hostile takeover to form Foremost-McKesson Inc. The Foremost dairy operations were sold in 1982 and the name changed to McKesson Corporation but headquarters remained in San Francisco. In 1999, McKesson acquired medical information systems firm HBO & Company (HBOC). Accounting irregularities at HBOC reduced the company's share price by half and resulted in the dismissal and prosecution of many HBOC executives. In 2001, the company's name reverted to McKesson. In 2019, the company relocated its headquarters from San Francisco to Irving, Texas, effective April 1, 2019. Also in April 2019, Brian Tyler took over as CEO. In February 2025, McKesson signed a definitive agreement to acquire 80% interest in PRISM Vision Holdings. In August 2026, the company was hacked by ShinyHunters.

Reader's Guide

McKesson Corporation's significance lies in its dominant role in the North American pharmaceutical supply chain, distributing a third of all pharmaceutical products used in the region. As the largest health care company in the United States by revenue, it has shaped the infrastructure of health care delivery through early adoption of technologies such as barcode scanning for distribution, pharmacy robotics, and RFID tags. Its legacy is complex: during the COVID-19 pandemic, McKesson served as the U.S. government's centralized distributor for hundreds of millions of COVID-19 vaccine doses and ancillary supply kits for over a billion doses, playing a critical role in public health. However, the company has also faced substantial legal and financial consequences for its role in the opioid epidemic. In 2008, McKesson paid $13 million in fines for failing to report large orders of hydrocodone. In January 2017, McKesson agreed to pay a $150 million civil penalty for alleged violations of the Controlled Substances Act regarding the distribution of opioids and another $150 million to settle allegations that it had not done enough to track and stop suspicious opioid sales. The agreement also obligated McKesson to suspend all sales of controlled substances from its distribution centers in Colorado, Florida, Ohio, and Michigan for multiple years. In January 2022, McKesson, AmerisourceBergen, Cardinal Health, and Johnson & Johnson agreed to pay $26 billion to settle with all but five of the states suing them. The 1938 McKesson and Robbins scandal, which exposed massive accounting fraud, led to lasting reforms in auditing and securities regulation. McKesson's history reflects both the power and the perils of a company central to the nation's health care system.

Did You Know?

• McKesson delivers a third of all pharmaceutical products used or consumed in North America.
• In 1938, one fourth of the company's $86,556,270 in assets was found to be fabricated figures in the McKesson and Robbins scandal.
• McKesson served as the U.S. government's centralized distributor for hundreds of millions of COVID-19 vaccine doses and ancillary supply kits for over a billion doses.
• In January 2022, McKesson and three other companies agreed to pay $26 billion to settle opioid lawsuits with all but five states.
• The company was hacked by ShinyHunters in August 2026.

Scale and Market Dominance

McKesson occupies a position in American healthcare that is almost difficult to conceptualize. The Irving, Texas–based firm moves roughly one-third of every pharmaceutical product used or consumed across North America, a share that places it at the center of the nation's medicine supply chain. With more than 80,000 employees on its payroll and 2024 revenue of $308.9 billion, it ranks as the ninth-largest company in the United States by revenue and stands as the country's single largest health care enterprise. Its business spans pharmaceutical distribution, medical supplies, health information technology, and health management tools, making it a one-stop infrastructure provider for providers, pharmacies, and patients alike. The stock trades on the New York Stock Exchange under the ticker MCK and is a constituent of the S&P 500, a listing that underscores its systemic importance to the broader U.S. economy. No other firm touches so many points of the daily flow of medicine in North America.

A Long and Turbulent Corporate History

The company's roots stretch back to 1828, when Charles M. Olcott opened a small New York City operation importing and wholesaling botanical drugs. After a partnership with John McKesson in 1833 and the later addition of Daniel Robbins, the firm cycled through several names before settling on McKesson & Robbins following Olcott's death in 1853. The 20th century brought upheaval: in 1938, CEO Phillip Musica was exposed for fabricating roughly a quarter of the company's $86,556,270 in assets to mask theft, triggering one of the most notorious accounting scandals of the era and reshaping American auditing and securities law. The firm survived through an equity receivership. In 1967, Foremost Dairies executed a hostile takeover, and the dairy operations were eventually shed in 1982. The 1999 acquisition of HBOC brought new trouble when accounting irregularities at that firm halved McKesson's share price and led to executive prosecutions. A series of 21st-century acquisitions—Per Se Technologies, RelayHealth in 2006, Practice Partner in 2007, NDCHealth Corporation in 2006, US Oncology in 2010 for $2.16 billion, PSS World Medical in 2013, and Celesio in 2014—transformed the firm into a global health-care giant.

The Opioid Crisis and Legal Reckoning

McKesson's relationship with the opioid epidemic has been marked by repeated legal and financial consequences. In 2008, the company paid a $13 million fine for failing to report large orders of hydrocodone. A far larger reckoning followed in January 2017, when McKesson agreed to a $150 million civil penalty for violations of the Controlled Substances Act tied to opioid distribution and an additional $150 million to settle claims that it had not done enough to track and stop suspicious sales. That settlement also required the company to suspend controlled-substance sales from distribution centers in Colorado, Florida, Ohio, and Michigan for multiple years. State-level litigation intensified in May 2020 when Oklahoma's attorney general Michael J. Hunter sued McKesson alongside Cardinal Health and AmerisourceBergen, alleging the three distributors supplied enough opioids for every adult in Bryan County to hold 144 hydrocodone tablets. In January 2022, McKesson, AmerisourceBergen, Cardinal Health, and Johnson & Johnson collectively agreed to pay $26 billion to settle with all but five of the suing states—a figure that averted potential penalties of up to $95 billion had the cases gone to trial.

Pandemic Logistics and Technological Footprint

When the novel coronavirus swept through the United States, McKesson stepped into a role of national significance. In August 2020, the CDC and HHS selected the company as the U.S. government's centralized distributor for hundreds of millions of COVID-19 vaccine doses, along with ancillary supply kits for over a billion doses. That assignment placed McKesson at the logistical heart of the nation's immunization effort, leveraging the extensive distribution infrastructure it had built over nearly two centuries. The company's operational DNA has long favored early adoption of technology: it was among the first in its sector to deploy barcode scanning for distribution, pharmacy robotics, and RFID tagging, all of which sharpened the speed and accuracy of moving product through its network. More recently, the firm continued to expand its footprint, signing a definitive agreement in February 2025 to acquire an 80% interest in PRISM Vision Holdings. Yet the company's digital exposure also carries risk; in August 2026, McKesson fell victim to a cyberattack carried out by the group known as ShinyHunters, a reminder that the same connected infrastructure that powers its scale can also be a target.

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