The Wall Street Journal reports that finalized rates for big health insurance plans around the country show the magnitude of the challenge facing the Obama administration as it seeks to stabilize the insurance market under the Affordable Care Act in its remaining weeks in office.

Market leaders that are continuing to sell coverage through HealthCare.gov or a state equivalent have been granted average premium increases of 30% or more in Alabama, Delaware, Hawaii, Kansas, Mississippi and Texas.

In states including Arizona, Illinois, Montana, Oklahoma, Pennsylvania and Tennessee, the approved rate increases for the market leader top 50%. In New Mexico, the Blue Cross Blue Shield plan agreed to resume selling plans through the online exchanges after sitting out last year, but has been allowed to increase rates 93% on their 2015 level.

Dominant insurers in Connecticut, Georgia, Indiana, Kentucky, Maine, Maryland and Oregon have been allowed to raise premiums by 20% or more, and rate increases from similarly situated carriers in Colorado, Florida and Idaho are brushing up against that threshold.

The Obama administration has characterized the year as one of “transition,” in part because insurers priced aggressively low in the opening enrollment periods for coverage under the law, and has pledged new efforts to encourage healthier people to sign up.

“The situation is serious,” said Alissa Fox, senior vice president of the Office of Policy and Representation for the Blue Cross Blue Shield Association. “The reason the premiums are where they are is that the people we are covering have serious conditions and they’re using a lot of medical services because of their chronic illnesses. That’s clear. And there’s not enough young, healthy people to balance out those costs.”

House Speaker Paul Ryan, a Wisconsin Republican, said the insurance markets are already in a “death spiral,’” and that “we’re going to have to change this thing.”

Insurers had warned of a turbulent year as they came to terms with the impact of sicker people rushing forward to buy insurance under new rules that required them to accept all buyers regardless of their medical history. A number of popular plans have folded, such as the “cooperative” startups funded by the law, sparking an exodus of their members onto the remaining insurers.

The danger for insurers and supporters of the law now is that high prices and limited choices further deter low-risk people from signing up, and that the increases continue and become irreversible.