WASHINGTON — Three influential Republican members of Congress unveiled a comprehensive proposal on Wednesday to replace President Obama’s health care overhaul with an alternative that would halt the expansion of Medicaid and scale back subsidies for middle-income people to buy private insurance.

The plan, drafted with encouragement from Republican leaders in the Senate and the House, would retain some consumer protections in the Affordable Care Act, but would reduce federal regulation of insurance policies. States would have more authority to specify the “essential health benefits” that must be provided by insurance. As an example, the federal government would no longer require insurance policies to include coverage for maternity care.

The proposal was devised by Senator Orrin G. Hatch of Utah, the chairman of the Finance Committee; Representative Fred Upton of Michigan, the chairman of the Energy and Commerce Committee; and Senator Richard M. Burr of North Carolina, a member of the Finance and Health committees.

In documents sketching their proposal, Republicans said their “blueprint” would lower costs and rebut criticism from Democrats who say the Republicans have no ideas on health care.