Medicare chief Marilyn Tavenner pauses while testifying on Capitol Hill in Washington, Nov. 5, 2013, before the Senate Health, Education, Labor, and Pensions Committee hearing as the panel seeks reassurances about problems with the debut of the Affordable Care Act (J. Scott Applewhite/AP)

More than 17 million Americans are eligible for tax credits when they purchase health care under the Affordable Care Act, according to a new report from the Kaiser Family Foundation, while as many as 29 million people could end up purchasing health-care coverage from state and federally-run marketplaces.

The Affordable Care Act makes people with incomes between 100 percent and 400 percent of the federal poverty limit eligible for tax credits when they buy their health-care coverage through the marketplaces. That doesn’t include anyone eligible for Medicaid, anyone who already receives benefits through their employers or anyone in the country illegally.

That means a family of four that earns between $23,550, the federal poverty line, and $94,200 would be eligible for subsidies, provided their employers don’t already cover them. Parents whose children are eligible for CHIP programs, too, aren’t included in the tax credit estimates.

The Kaiser report shows more than one million people are eligible for tax credits in Texas, California and Florida. Another seven states have at least half a million people who would be eligible for credits.

Estimated residents eligible for tax credits:

(Source: Kaiser Family Foundation)

Six states and the District of Columbia all have fewer than 50,000 residents eligible for tax credits.

But the number of Americans who might seek to be covered by the marketplaces is almost twice as high as the number of residents covered by tax credits. Up to 29 million people who currently purchase non-group health insurance and uninsured Americans who aren’t eligible for Medicaid or CHIP programs might look to the markets to buy their coverage, the report found.

That figure didn’t include those who make too much to qualify for Medicaid but who wouldn’t have the means to purchase insurance on their own, the so-called “gap group.” It also doesn’t include the uninsured who live in the home of a full-time worker who receives health care through their employers.

Potential market size by state:

(Source: Kaiser Family Foundation)

The Congressional Budget Office has estimated that 7 million people will enroll in the federal and state-run health insurance exchanges. Six million of those people are likely to receive a tax credit to subsidize their premium, CBO estimated.

After a rocky rollout that has been plagued by Web site blackouts and other headaches, an Obama administration official said Tuesday the administration would release statistics on the number of people who were able to enroll in health insurance exchanges through the new online marketplaces. Marilyn Tavenner, the administrator of the Centers for Medicare and Medicaid Services, tried at a Senate committee hearing to tamp down expectations. Tavenner said the administration expected peak enrollment to come in the middle of December.

Enrollment in the public exchanges is expected to triple by 2016. But it’s likely that those who sign up earliest will be the sickest — those who have preexisting conditions and haven’t been eligible for previous plans, for example.

“Low enrollment levels may indicate a disproportionately sick risk pool, while higher enrollment levels may suggest a more balanced pool,” the Kaiser authors wrote.