WASHINGTON (AP) – Cancer patients could face high costs for medications under President Barack Obama’s health care law, industry analysts and advocates warn.

Where you live could make a huge difference in what you’ll pay.

To try to keep premiums low, some states are allowing insurers to charge patients a hefty share of the cost for expensive medications used to treat cancer, multiple sclerosis, rheumatoid arthritis and other life-altering chronic diseases.

Such "specialty drugs" can cost thousands of dollars a month, and in California, patients would pay up to 30 percent of the cost. For one widely used cancer drug, Gleevec, the patient could pay more than $2,000 for a month’s supply, says the Leukemia & Lymphoma Society.

New York is taking a different approach, setting flat dollar copayments for medications. The highest is $70, and it would apply to specialty drugs as well.

Critics fear most states will follow California’s lead, and that could defeat the purpose of Obama’s overhaul, because some of the sickest patients may be unable to afford their prescriptions.

"It’s important that the benefit design not discriminate against people with chronic illness, and high copays do that," said Dan Mendelson, president of Avalere Health, a data analysis firm catering to the health care industry and government.

Avalere’s research shows that 1 in 4 cancer patients walks away from the pharmacy counter empty-handed when facing a copay of $500 or more for a newly prescribed drug.

"You have to worry about a world where if you happen to contract cancer or multiple sclerosis, you are stuck with a really big bill," Mendelson said. "It’s going to be very important for states to take a long, hard look at their benefit design."

Although the money for covering uninsured Americans is coming from Washington, the heath care law gives states broad leeway to tailor benefits, and the local approach can also allow disparities to emerge.

A spokesman for Covered California said state officials are trying to balance between two conflicting priorities: comprehensive coverage and affordable premiums.

"We are trying to keep the insurance affordable across the board," said Dana Howard, the group’s spokesman. "This is just part of trying to manage the overall risk of the pool." Covered California is one of the new state marketplaces where people who don’t get coverage on the job will be able to shop for private insurance starting this fall. Coverage takes effect Jan. 1.

Insurers are forecasting double-digit premium increases for individual policies, as people with health problems flock to buy coverage previously denied them. The Obama administration says the industry warnings are overblown, and that for many consumers, premium increases will be offset by tax credits to help buy insurance. And officials say it’s important to realize that the law sets overall limits on patients’ liability, even if those seem high to some people. Still, a full picture of costs and benefits isn’t likely to come into focus until the fall.

Howard said California officials are aware of the concerns about drug costs and are trying to make medications more affordable.

Meanwhile, he said consumers will be protected because the law limits total out-of-pocket costs – the deductibles and copayments that policy holders are responsible for, apart from monthly premiums. In California, the annual out-of-pocket limit for an individual is $6,400, although it can be as low as $2,250 for low-income people. Once that limit is reached, insurance pays 100 percent.

That’s still a lot of money, and such reassurances haven’t dispelled the concerns.

"The intent of the Affordable Care Act is to make sure that all Americans have access to quality, affordable health care," said Brian Rosen, a senior vice president of the Leukemia & Lymphoma Society. He adds that there is a danger that the insurance marketplaces "will discriminate against the patients with the highest medical need. That would completely undermine the spirit of the ACA."

The group has been joined by Rep. Doris Matsui, D-Calif., in urging state officials to reconsider the policy. The high copays "could prevent many patients from receiving the lifesaving treatments they need because of prohibitively high cost," Matsui wrote to the state.

The problem with costly drugs is similar to another money issue with the health care law – a provision that could price millions of smokers out of coverage. Insurers are allowed to charge tobacco users buying an individual policy up to 50 percent higher premiums. For a 55-year-old smoker, the penalty could reach nearly $4,250 a year, on top of the standard premium. California is trying to override that problem by passing its own law. There’s also pending state legislation to address some issues with prescription costs, but its prospects are unclear.

Meanwhile, leukemia patient Lisa Lusk worries about what will happen to her. A nursing assistant who lives near Fresno, Lusk is hoping to return to work in the next few months. When that happens, she expects to lose emergency coverage she’s now getting through the state. And the medication Lusk takes to manage her chronic form of the disease costs more than $5,000 a month.

"I’m scared that when I get a job my copay may be more than $1,500 a month," said Lusk. "I’ll just be working to pay for my medications."