About 20 million Americans have gained health insurance or enrolled in new insurance under the health care reform law, according to a new report.

The report from the Commonwealth Fund, published Wednesday in the New England Journal of Medicine, credits President Barack Obama’s health reform law with an estimated 20 million enrollments as of May 1. The report looks at both people who gained coverage through insurance marketplaces, and people who gained coverage due to provisions in the Affordable Care Act (such as those qualifying for Medicaid and those now covered through the Children’s Health Insurance Program).

The authors estimate that 7.8 million people under 26—who are now allowed to be covered as dependents on their parents’ plans—have enrolled. They also report that 8 million people were enrolled in coverage via new health insurance marketplaces and five million purchased coverage directly from insurers.

The authors write that for ACA’s continued expansion to be sustainable, it will rely largely on the ability of the U.S. to control health care costs.

“Developing and spreading innovative approaches to health care delivery that provide greater quality at lower cost is the next great challenge facing the nation,” the report concludes.

The Commonwealth Fund

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