LOS ANGELES (AP) -- Most of those who might qualify for insurance coverage or tax breaks under President Barack Obama's health care overhaul don't know it, a poll released Wednesday found.

The Field Poll, surveying uninsured, lower-income voters who it said would qualify for coverage, found slightly more than half either did not know it or believed the opposite — that they were not eligible. Forty-eight percent were aware they could qualify, the poll found.

The margin was even wider for voters currently not covered by an employer or government program but who would qualify for tax credits when purchasing coverage under the Affordable Care Act, which takes full effect next year. Two of three of those voters either did not know about their eligibility for the tax breaks or thought they would not qualify.

With enrollment for the Affordable Care Act set to begin in October "the numbers are quite low" for awareness about the law and its provisions, poll Director Mark DiCamillo said. It shows "the magnitude of the job ahead."

The state agency guiding Obama's overhaul, Covered California, is beginning the task of trying to reach millions of people without insurance and sway them to sign up while overcoming geographic, language and cultural barriers.

California could see more than $300 million invested in television and online ads, billboards, door-to-door visits and other sales pitches and promotions to convince uninsured residents to enroll.

The findings are similar to those in a Field survey released earlier this week that found widespread confusion about the law among the broader population.

That poll, released Tuesday, found that one in four California voters knows little or nothing about the Affordable Care Act, while another 60 percent say they are only "somewhat knowledgeable" about it.

Under the president's program, people without access to coverage through their jobs can start shopping for subsidized, private insurance in new state markets called exchanges.

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The exchanges are supposed to transform the way individuals and small businesses buy private health insurance by increasing transparency and competition, bolstering oversight of insurers and injecting hundreds of billions of dollars in taxpayer subsidies. Insurance companies will not be able to deny coverage to those with pre-existing medical conditions and will be required to offer more comprehensive care than what is generally available to individuals now.

Another major piece of the federal law is a Medicaid expansion to serve more low-income people. Open enrollment on the exchanges begins Oct. 1, with the benefits kicking in Jan. 1.

The Field Poll conducted a random telephone survey of about 1,200 voters, supplemented by interviews with nearly 500 minority voters. The poll was conducted from June 26 to July 21, and has a margin of error of plus or minus 2.6 percentage points.