A newly formed coalition of health care leaders in Massachusetts says repealing Obamacare — as congressional Republicans have vowed — could affect the state more than people realize.

Massachusetts passed a health reform law in 2006, before the Affordable Care Act, that was a model for President Obama’s program.

The state has since provided subsidized health insurance to thousands of residents. But to do that, Audrey Shelto, president of the Blue Cross Blue Shield of Massachusetts Foundation, said the state relies on federal support.

“While there may be structural authorities and components we would be able to turn back to, in terms of health care reform and coverage in Massachusetts,” Shelto said, “a significant portion of the funding would be contingent on getting federal dollars from Washington.”

Shelto said the new coalition is strategizing ways to explain the risks of rolling back health reform to policy makers. They plan to reach out to those beyond Massachusetts, where there’s less support for universal coverage.