WASHINGTON (AP) — Here's a reality check for President Barack Obama's health overhaul: Three out of four uninsured Americans live in states that have yet to figure out how to deliver on its promise of affordable medical care.

This is the year that will make or break the health care law. States were supposed to be partners in carrying out the biggest safety net expansion since Medicare and Medicaid, and the White House claims they're making steady progress.

But an analysis by The Associated Press shows that states are moving in fits and starts. Combined with new insurance coverage estimates from the nonpartisan Urban Institute, it reveals a patchwork nation.

Such uneven progress could have real consequences.

If it continues, it will mean disparities and delays from state to state in carrying out an immense expansion of health insurance scheduled in the law for 2014. That could happen even if the Supreme Court upholds Obama's law, called the Patient Protection and Affordable Care Act.

"There will be something there, but if it doesn't mesh with the state's culture and if the state is not really supporting it, that certainly won't help it succeed," said Urban Institute senior researcher Matthew Buettgens.

The 13 states that have adopted a plan are home to only 1 in 4 of the uninsured. An additional 17 states are making headway, but it's not clear all will succeed. The 20 states lagging behind account for the biggest share of the uninsured, 42 percent.

Among the lagging states are four with arguably the most to gain. Texas, Florida, Georgia and Ohio together would add more than 7 million people to the insurance rolls, according to Urban Institute estimates, reducing the annual burden of charity care by $10.7 billion.

"It's not that we want something for free, but we want something we can afford," said Vicki McCuistion of Driftwood, Texas, who works two part-time jobs and is uninsured. With the nation's highest uninsured rate, her state has made little progress.

The Obama administration says McCuistion and others in the same predicament have nothing to fear. "The fact of states moving at different rates does not create disparities for a particular state's uninsured population," said Steve Larsen, director of the Center for Consumer Information and Insurance Oversight at the federal Department of Health and Human Services.

That's because the law says that if a state isn't ready, the federal government will step in. Larsen insists the government will be ready, but it's not as easy as handing out insurance cards.

Someone has to set up health insurance exchanges, new one-stop supermarkets with online and landline capabilities for those who buy coverage individually.

A secure infrastructure must be created to verify income, legal residency and other personal information, and smooth enrollment in private insurance plans or Medicaid. Many middle-class households will be eligible for tax credits to help pay premiums for private coverage. Separate exchanges must be created for small businesses.

"It's a very heavy lift," said California's health secretary, Diana Dooley, whose state was one of the first to approve a plan. "Coverage is certainly important, but it's not the only part. It is very complex."

California has nearly 7.5 million residents without coverage, more than half of the 12.7 million uninsured in the states with a plan. An estimated 2.9 million Californians would gain coverage, according to the Urban Institute's research, funded by the nonpartisan Robert Wood Johnson Foundation.

Democrats who wrote the overhaul law had hoped that most states would be willing partners, putting aside partisan differences to build the exchanges and help cover more than 30 million uninsured nationally. It's not turning out that way.

Some states, mainly those led by Democrats, are far along. Others, usually led by Republicans, have done little. Separately, about half the states are suing to overturn the law.

Time is running out for states, which must have their plans ready for a federal approval deadline of Jan. 1, 2013. Those not ready risk triggering the default requirement that Washington run their exchange.

Yet in states where Republican repudiation of the health care law has blocked exchanges, there's little incentive to advance before the Supreme Court rules. A decision is expected this summer, and many state legislatures aren't scheduled to meet past late spring.

The result if the law is upheld could be greater federal sway over health care in the states, the very outcome conservatives say they want to prevent.

"If you give states the opportunity to decide their own destiny, and some choose to ignore it for partisan reasons, they almost make the case against themselves for more federal intervention," said Sen. Ben Nelson, D-Neb.

A conservative, Nelson was on the winning side of a heated argument among Democrats over who should run exchanges, the feds or the states. Liberals lost their demand for a federal exchange, insulated from state politics.

"It's pretty hard to take care of the states when they don't take care of themselves," said Nelson, who regrets that the concession he fought for has been dismissed by so many states.

The AP's analysis divided states into four broad groups: those that have adopted a plan for exchanges, those that made substantial progress, those where the outlook is unclear, and those with no significant progress. AP statehouse reporters were consulted in cases of conflicting information.

Thirteen states, plus the District of Columbia, have adopted a plan.

By contrast, in 20 states either the outlook is unclear or there has been no significant progress. Those states include more than 21 million of the 50 million uninsured Americans.

Four have made no significant progress. They are Arkansas, Florida, Louisiana and New Hampshire. The last three returned planning money to the federal government. In Arkansas, Democratic Gov. Mike Beebe ran into immovable GOP opposition in the Legislature. Beebe acknowledges that the federal government will have to run the exchange, but is exploring a fallback option.

In the other 16 states, the outlook is unclear because of failure to advance legislation or paralyzing political disputes that often pit Republicans fervently trying to stop what they deride as "Obamacare" against fellow Republicans who are more pragmatic.

In Kansas, for example, Insurance Commissioner Sandy Praeger is pushing hard for a state exchange, but Gov. Sam Brownback returned a $31 million federal grant, saying the state would not act before the Supreme Court rules. Both officials are Republicans.

"It's just presidential politics," said Praeger, discussing the situation nationally. "It's less about whether exchanges make sense and more about trying to repeal the whole law." As a result, outlook is unclear for a state with 361,000 uninsured residents.

There is a bright spot for Obama and backers of the law.

An additional 17 states have made substantial progress, although that's no guarantee of success. Last week in Wisconsin, GOP Gov. Scott Walker abruptly halted planning and announced he will return $38 million in federal money.

The AP defined states making substantial progress as ones where governors or legislatures have made a significant commitment to set up exchanges. Another important factor was state acceptance of a federal exchange establishment grant.

That group accounts for just under one-third of the uninsured, about 16 million people.

It includes populous states such as New York, Illinois, North Carolina and New Jersey, which combined would add more than 3 million people to the insurance rolls.

Several are led by Republican governors, including Virginia and Indiana, which have declared their intent to establish insurance exchanges under certain conditions. Other states that have advanced under Republican governors include Arizona and New Mexico.

For uninsured people living in states that have done little, the situation is demoralizing.

Gov. Rick Perry's opposition to the law scuttled plans to advance an exchange bill in the Texas Legislature last year, when Perry was contemplating his presidential run. The Legislature doesn't meet this year, so the situation is unclear.

McCuistion and her husband, Dan, are among the nearly 6.7 million Texans who lack coverage. Dan is self-employed as the owner of a specialty tree service. Vicki works part time for two nonprofit organizations. The McCuistions have been uninsured throughout their 17-year marriage, although their three daughters now have coverage through the Children's Health Insurance Program. Dan McCuistion has been nursing a bad back for years, and it only seems to get worse.

"For me it almost feels like a ticking time bomb," his wife said.

Dan McCuistion says he doesn't believe Americans have a constitutional right to health care, but he would take advantage of affordable coverage if it was offered to him. He's exasperated with Perry and other Texas politicians. "They give a lot of rhetoric toward families, but their actions don't meet up with what they are saying," he said.

Perry's office says it's principle, not lack of compassion.

"Gov. Perry believes 'Obamacare' is unconstitutional, misguided and unsustainable, and Texas, along with other states, is taking legal action to end this massive government overreach," said spokeswoman Lucy Nashed. "There are no plans to implement an exchange."