A study released today finds that between 29.8 million and 31.0 million people will remain uninsured after the implementation of the Affordable Care Act in 2016.

The research team from Harvard Medical School and the City University of New York School of Public Health projects that the demographic composition of today’s uninsured population will change little under Obamacare.

The share of the uninsured who are U.S. citizens will rise slightly from 80 percent to 81 percent.

White persons (of all ethnicities) will continue to constitute 74 percent of all uninsured Americans.

About 59 percent of the uninsured will have incomes between 100 percent and 399 percent of poverty, while 27 percent will have incomes below poverty.

The study analyzed Census Bureau data on current patterns of uninsurance, and used a coverage prediction model based on the model used by the Congressional Budget Office.

The researchers projected two coverage scenarios for each state.

One assumed that the state turns down a Medicaid expansion and the other assumed that the state implements Medicaid expansion despite the Supreme Court ruling that such expansion is optional.

The national estimates use the Advisory Board Company’s latest summary of which states are likely to participate in the Medicaid expansion.

“Many people believe that Obamacare will cover everyone,” said study co-author Dr. Steffie Woolhandler, a professor at CUNY and a visiting professor of medicine at Harvard. “But the reform is so deeply flawed that 30 million or more will still be uninsured after it’s fully implemented. Even if the Supreme Court hadn’t let states of the hook for Medicaid expansion, 26 million would have been uninsured. We need to replace Obamacare with a simple single-payer system that would cover everyone.”

“Even in Massachusetts, where a reform like Obamacare has been in place since 2006, too many patients still can’t get the care they need,” said lead author Dr. Rachel Nardin, chief of neurology at Cambridge Health Alliance and assistant professor of neurology at Harvard. “Hundreds of thousands are still uninsured, and many more have such skimpy coverage that they face unaffordable co-payments.”