The origins of Kaiser Permanente began during the Great Depression in 1933 in the Mojave Desert of California. Dr. Sidney R. Garfield opened a modest 12-bed desert hospital in Mojave to treat thousands of construction workers building the Los Angeles Aqueduct. Garfield faced financial ruin as injured workers could not pay their medical bills, and insurance companies were slow to reimburse. Harold Hatch, an insurance agent, proposed a revolutionary solution: insurance companies would prepay Dr. Garfield a fixed sum of 17.5 cents per worker per week, and workers would contribute five cents a week. This prepaid prepayment system stabilized Garfield's hospital and fundamentally aligned incentives: keeping workers safe and healthy saved money, while sickness created costs. In 1938, industrial titan Henry J. Kaiser, who was building the Grand Coulee Dam in Washington, recruited Dr. Garfield to provide prepaid medical care to 6,500 dam workers and their families. During World War II, Kaiser and Garfield expanded the system to care for more than 190,000 workers at Kaiser's colossal shipyards in Richmond, California, and Portland, Oregon. When the war ended in 1945, Henry Kaiser and Dr. Garfield officially opened the health plan to the general public, establishing Kaiser Permanente on October 1, 1945, and permanently pioneering modern integrated HMO medicine. In the decades following its initial founding, Kaiser Permanente navigated rapid industry evolutions, transitioning from early legacy operating paradigms to modern integrated operations. This sustained focus allowed the company to survive cyclical macroeconomic contractions, outpace regional incumbents, and establish deep institutional trust with demanding stakeholders. Through disciplined capital allocation, continuous internal innovation, and targeted strategic initiatives, Kaiser Permanente built an enduring competitive moat anchored by proprietary technology, deep domain expertise, and sticky relationships that resist structural disruption.