(Bloomberg News) To Megan Hildebrandt, President Barack Obama’s Affordable Care Act means she can no longer be denied health insurance because of her lymphatic cancer.

There’s a big catch: Coverage for the 28-year-old artist and many other Americans without insurance will come at a potentially unaffordable cost.

Hildebrandt, who relies on hospital charity, will face more than $1,000 in annual premiums, by one estimate, and probably more in out-of-pocket expenses even with new federal subsidies. She and her husband have a combined income of $25,000.

“It’s great that I’m not going to have to pay some hugely impossible amount,” said Hildebrandt, who lives in Austin, Texas. “Though now I’m in the health-care system and still have to pay money that we can’t really afford.”

The landmark health-care law, which survived the threats of repeal and a Supreme Court review, now confronts another hurdle: living up to expectations. As the administration spells out the details, many uninsured will be surprised at how much they will have to pay. It may involve “very substantial amounts,” and “there still will be a significant number of people who can’t afford health coverage,” said Ron Pollack, head of Families USA, a consumer group that backs the law.

A family of four earning $75,000 will pay $7,125 in annual premiums and as much as $8,333 in co-pays and deductibles, according to a preliminary estimate by the Kaiser Family Foundation. A single 40-year-old earning $30,000 will pay $2,509 in premiums and as much as $3,125 in cost sharing. For a 60- year-old making $40,000, the amount will be $3,800 in premiums and up to $4,167 in out-of-pocket costs, according to Kaiser.

New Rules

Those costs will come even as the government spends about $1.16 trillion over the next decade to expand coverage to 30 million uninsured people. The administration last week unveiled regulations to implement the ban on discriminating against those with preexisting conditions. Insurers would be limited to varying premiums by age, family size, geography and tobacco use.

To be sure, the costs will be far less than what many with preexisting conditions would pay in the absence of the overhaul. The law is also designed to reduce expenses for those who already have insurance because hospitals providing charitable care make up those costs by charging others more.

“While we’re only dimly aware of it, we all pay,” said former Congressional Budget Office Director Robert Reischauer. “There shouldn’t be free-riders.”