President Donald Trump’s decision to end a provision of the Affordable Care Act that lowered out-of-pocket medical costs for millions of Americans has brought swift reaction from the states.

Health officials and consumers today said they feared the action could chase millions away from coverage.

Attorneys general in several states, including California, Connecticut, Kentucky, Massachusetts and New York, said they planned to sue the Trump administration to keep the money flowing.

At issue is a federal subsidy for deductibles and co-pays that helps lower costs for consumers with modest incomes. The Trump administration and many Republicans say the government cannot legally continue to make the so-called cost-sharing payments.

State officials say ending the subsidies will make insurance premiums skyrocket, forcing some consumers to give up having coverage at all.