From the article:

    The fallout from the hack of a little-known but pivotal health-care company is inflicting pain on hospitals, doctor offices, pharmacies and millions of patients across the nation, with government and industry officials calling it one of the most serious attacks on the health-care system in U.S. history.

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    Change Healthcare is a juggernaut in the health-care world, processing 15 billion claims totaling more than $1.5 trillion a year, the company says. It operates the largest electronic “clearinghouse” in the business, acting as a pipeline that connects health-care providers with insurance companies who pay for their services and determine what patients owe. It supported tens of thousands of physicians, dentists, pharmacies and hospitals, handling 50 percent of all medical claims in the United States, the Justice Department wrote in a 2022 lawsuit that unsuccessfully tried to block UnitedHealth from acquiring the company.