WASHINGTON — A health care overhaul bill that the House could vote on as soon as tomorrow contains language to ensure that Hawaii's expansive health coverage requirements wouldn't be weakened.

Specifically, provisions inserted into the almost 2,000-page bill by Hawaii's congressional delegation would protect the state's Prepaid Health Care Act of 1974 from any changes imposed by the new federal legislation.

The health care act requires nearly all employers in Hawaii to provide health insurance to employees who work at least 20 hours a week for four consecutive weeks.

"For Hawaii, it's really critical that this doesn't get swept aside as we deal with health care reform," said U.S. Rep. Mazie Hirono, D-Hawaii, who wrote the House provisions that would retain Hawaii's coverage.

Both of Hawaii's House lawmakers are expected to vote in favor of the bill.

"I'm doing everything in my power to ensure Ha-waii's existing laws are protected," said U.S. Rep. Neil Abercrombie, D-Hawaii, who is running for governor.

The Senate does not have a complete health care bill and might not until next year.

Hawaii's insurance requirements are credited with making it the second most medically insured state in the nation, behind Massachusetts. More than 92 percent of Hawaii residents have insurance, according to the independent Kaiser Family Foundation. About 84 percent of the nation is insured.

"Hawaii is one of the healthiest states in the country, partly because of access," said U.S. Sen. Daniel K. Inouye, D-Hawaii.

The House bill would spend $1.1 trillion over 10 years insuring 36 million Americans who don't have coverage, according to the Congressional Budget Office. But it would reduce the deficit by $104 billion through new taxes, spending cuts in Medicare and Medicaid, and penalties levied on people and businesses that don't buy insurance.

Major provisions of the bill would take effect in 2013.

The number of people eligible for the federal-state Medicaid program would increase, a proposal that many governors say they would have trouble financing.

And the bill would bar insurers from turning away customers because of pre-existing health conditions.

Individuals and smaller employers could get coverage on a new health insurance exchange, and the government would provide subsidies to help lower-income people afford it. The exchange would include a government-run "public" insurance program that the CBO says would enroll about 6 million people, or 2 percent of Americans under 65.

Abercrombie and Hirono support a public option.

Under the bill, everyone would be required to get insurance.

A Hawaii exemption is in one of the two health care bills the Senate must merge to create a final version.

"It is essential that we protect Hawaii's waiver," said Democratic U.S. Sen. Daniel Akaka, who wrote the Senate version of the exemption for Hawaii. Akaka does not anticipate any serious opposition to his provision.

Hawaii's maneuvering to protect its health insurance requirement is part of a national frenzy of health care analysis by states trying to figure out what will come out of Washington.

"Right now everybody is looking at the various (health care) bills and thinking what this would mean for them," said Judith Solomon, a senior fellow at the Center on Budget and Policy Priorities in Washington. "But it's still difficult now because we still don't have anything final."

The House vote might come by tomorrow, but not without input from Republicans, who say they've been largely shut out from the crafting of the legislation.

House Republicans plan to introduce a health care proposal of their own this week. House Minority Leader John Boehner of Ohio said that proposal would not raise taxes or require people or businesses to buy health insurance. The proposal would allow families and businesses to buy health insurance across state lines and would impose a $250,000 limit on noneconomic damages in medical malpractice suits.

The GOP proposal would not bar insurance companies from denying coverage based on pre-existing conditions and would not create tax credits to help people buy coverage.