McKesson provides extensive network of infrastructure for the healthcare industry and was an early adopter of technologies, including barcode scanning for distribution, pharmacy robotics, and RFID tags.

In 1967, Foremost Dairies, a company founded by James Cash Penney, which was headquartered in San Francisco since 1954, acquired McKesson & Robbins in a hostile takeover[10] to form Foremost-McKesson Inc.[11] The Foremost dairy operations were sold in 1982 and the name changed to McKesson Corporation but headquarters remained in San Francisco.

[21] In April 2012, McKesson agreed to pay the United States $190M to settle allegations that it had inflated prices and overbilled Medicaid.

[22] Three months later, in July 2012, McKesson agreed to pay California and 28 other states $151M to settle allegations that it had inflated prices and overbilled Medicaid.

[27][28] In November 2018, the company announced it would relocate its headquarters from San Francisco to Irving, Texas, effective April 1, 2019.

[33] In January 2017, McKesson agreed to pay a $150 million civil penalty for alleged similar violations of the Controlled Substances Act regarding the distribution of opioids.

[34] In January 2017, McKesson agreed to pay $150M to settle allegations that it had not done enough to track and stop suspicious opioid sales.

[35] 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.

Hunter sued McKesson in Bryan County District Court, alleging that the company's actions helped fuel Oklahoma's opioid crisis.

[38] In August 2020, during the COVID-19 pandemic, the CDC and HHS selected McKesson as the U.S. government's centralized distributor for COVID-19 vaccine doses and ancillary supply kits under Operation Warp Speed.

Their online medical supply ordering platform serves the needs of physician offices, surgery centers, home health agencies, DMEs, labs, and long-term-care facilities.

[51] In March 2016, McKesson agreed to purchase Canadian pharmacy chain Rexall from the Katz Group of Companies for $3 billion.

McKesson's United Kingdom base was in Warwick with data centers in Newcastle upon Tyne and Brent Cross and offices in Sheffield, Bangor, Glasgow and Vauxhall, London.

In 2014, McKesson sold most of their healthcare software business to the private equity firm Symphony Technology Group and indicated also that they would not be re-bidding for the Electronic Staff Record contract.

The company employs approximately 40 team members across Australia and New Zealand, including general management, R&D, sales, services, and support employees.

McKesson Capacity Planne, formerly Emendo CapPlan, is used in more than 40 hospitals in Australia, New Zealand, Britain, Canada, and the U.S.[64] to forecast future patient activity and help health systems to allocate resources efficiently and identify unnecessary costs.

[63][65] On November 2, 2020, Walgreens Boots Alliance (WBA) and McKesson announced the completion of their previously announced agreement to create a joint venture combining their respective pharmaceutical wholesale businesses in Germany, Alliance Healthcare Deutschland (AHD) and GEHE Pharma Handel (GEHE).