Cerner Corporation is an American supplier of health information technology (HIT) solutions, services, devices and hardware. As of April 2015 its products were in use in approximately 18,000 facilities around the world and the company had about 25,000 employees globally.

Cerner was founded in 1979 by Neal Patterson, Paul Gorup, and Cliff Illig, who were colleagues at Arthur Andersen. Its original name was PGI & Associates but was renamed Cerner in 1984 when it rolled out its first system, PathNet. It went public in 1986. Cerner's client base grew steadily in the late 1980s, reaching 70 sites in 1987, 120 sites in 1988, 170 sites in 1989, and reaching 250 sites in 1990. Installations were primarily of PathNet systems.

During this time, Cerner was developing components of a Health Network Architecture (HNA), an integrated IT system designed to automate health care processes. Clients could purchase individual components or the whole system at one time. By 1994, more than 30 clients had purchased the full HNA system, while 100 clients had purchased multiple components of the system.

In 1997, the company introduced Cerner Millennium, an upgrade to its HNA system which incorporated all of the company’s software offerings into one unified architecture. The introduction of Millennium contributed to significant growth for the company, with revenue increasing to $1.1 billion in 2005 from $245.1 million in 1997.

Cerner acquired IMC Health Care, Inc. in early 2010 to continue expanding its wellness services to outside commercial employers, pharmacies and wellness programs.

In July 2010, president Trace Devanny left the company and Patterson became the company’s president, in addition to his roles as chairman and chief executive officer. In September 2013, Zane Burke was named president, assuming the title from Patterson.

On August 5, 2014, Cerner announced its intent to purchase Siemens Health Services, the health information technology business of Germany’s Siemens AG, for $1.3 billion. The acquisition was completed on February 2, 2015.

On July 29, 2015, Leidos Partnership for Defense Health, which includes Cerner, Accenture, and Leidos, was awarded a 10-year, $4.3 billion contract to overhaul and manage the electronic health records for the Department of Defense.

CEO and co-founder Neal Patterson died July 9, 2017.

In 2001, a memo authored by CEO Patterson and sent to about 400 managers was leaked online. The memo, written in harsh language, was meant to motivate the managers to get more productivity out of employees and promised layoffs, a hiring freeze, closing of an "Associate Center", and the implementation of a punch-card system if Patterson did not see evidence of changes. Patterson's metric was the fullness of the company's Kansas City office lot at the hours of 8 a.m. and 5 p.m. The memo was widely seen as inflammatory and poor management, and Cerner's stock price fell 22% over three days.

In 2002, the installation of a computerized health system by Cerner in the Children's Hospital of Pittsburgh of UPMC made it harder for the doctors and nurses to do their jobs in emergency situations and resulted in a "disaster", according to Phillip Longman, a senior fellow at the New America Foundation. Longman wrote, "According to a study conducted by the hospital and published in the journal Pediatrics, mortality rates for one vulnerable patient population—those brought by emergency transport from other facilities—more than doubled, from 2.8 percent before the installation to almost 6.6 percent afterward." Defenders of Cerner in the study charged that the Pittsburgh hospital did not adequately prepare for the transition to the CPOE system in that it had at the same time significantly changed its pharmacy process, did not provide adequate wireless bandwidth, and did not have order sets pre-programmed on day one. They noted that other hospitals that more carefully planned the implementation did not experience the same problems.

In 2005, Cerner and other companies paid for a report by the RAND Corporation which predicted great efficiencies from electronic health records, including savings of $81 billion a year or more, which RAND now says is overstated. This report helped drive growth in the electronic health record and billions of dollars in federal incentives to hospitals and doctors. Cerner's revenue tripled from $1 billion in 2005 to a projected $3 billion in 2013. The study was criticized by the Congressional Budget Office for overstating potential savings. A 2013 reassessment of the 2005 report by the RAND Corporation said that the conversion had failed to produce savings and had mixed results in efficiency and patient care.

In 2010 Girard Medical Center, Crawford County, Kansas, hired Cerner to install an electronic records system. But after receiving $1.3 million, Cerner employees failed to get the system running in time to qualify for federal incentive payments, and in September 2011 notified the hospital that it was abandoning the project, according to a lawsuit Girard filed against Cerner. Cerner and executives at Girard agreed that Girard did not have adequate staff to manage the acquisition and implementation of the system. As of June 2014 the case was still in arbitration.

In 2012 Trinity Health, a small hospital in North Dakota, sued Cerner, claiming that Cerner's patient accounting solution didn't work correctly; the parties settled for $106M in 2014.

In 2014, Cerner was embroiled in litigation with the Girard case still unsettled, a grand jury in California having found that Cerner knew that Ventura County healthcare executives were unprepared to work with Cerner in a $32 million installation, and with a $31 million Cerner implementation at the Athens Regional Health System in Georgia having turned into a disaster, leading to the forced departures of the CEO and the CIO of the health system.

In 2016, the Nanaimo hospital ER began using the system. Physicians have called it a "huge failure" with it increasing some types of errors and slowing down the emergency department.

Cerner's world headquarters campus is at 2800 Rockcreek Parkway, North Kansas City, Missouri. It acquired additional space in Kansas City, Missouri in 2005 and in 2006 it acquired another location in Kansas City. In 2013, Cerner announced plans to redevelop 236-acres in south Kansas City, Missouri into an office park. The site was previously occupied by Bannister Mall, which was demolished in 2009. Cerner broke ground on the new campus on November 11, 2014. The $4.45 billion project intends to employ 16,000 new Cerner workers within the decade.

Cerner has offices in about 25 countries worldwide.

The North tower of Cerner Continuous Campus in Kansas City, KS

Since 2006 Cerner has also occupied space in the former Marion Laboratories in Kansas City

Ground floor of Cerner Innovations Campus in Kansas City, MO

Cerner Health Services building in Malvern, PA