"Repealing key parts of the ACA could trigger massive job losses and a slump in consumer and business spending that would affect all sectors of state economies," said Leighton Ku, director of the Center for Health Policy Research and professor at the Milken Institute School of Public Health at George Washington University.
Ku is the lead author of the report, which was issued by the Milken Institute and the Commonwealth Fund.
The report comes as President-elect Donald Trump and the new Congress are moving toward repealing parts of the ACA through the budget reconciliation process.
"The immediate and most visible effect of ACA repeal would be the loss of coverage and access to care for millions of people who have gained insurance because of the law," said Sara Collins, vice president for health-care coverage and access at the Commonwealth Fund.
"This study points to even larger potential economic effects that would be detrimental to the health and well-being of millions more," Collins said.
The estimate of job and state product losses are based on a scenario in which Congress defunds federal subsidies that most Obamacare customers receive to help lower their monthly insurance premium costs, and also gets rid of funding to cover adults who became newly eligible for Medicaid under the ACA.
Repealing both provisions would save the federal government $140 billion in health-care spending, the report found. And as that funding spigot dried up, it would lead to job losses and a drop in gross state product, the report said.
The study notes that most of the federal funding for Obamacare flows to hospitals, health clinics, pharmacies and other medical providers, who in turn hire and pay staff and purchase goods and services.