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.

On Friday, health officials and consumers 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.

"Today’s action is not about the president. It is about making the federal government keep its promises and protect the health and prosperity of our Kentucky families. The Kentucky Attorney General’s office has a record of filing suit when the federal government harms Kentucky families, including lawsuits against the last administration," Kentucky Attorney General Andy Beshear said in a statement.

State officials say ending the subsidies will make insurance premiums skyrocket, forcing some consumers to give up having coverage at all. The Foundation for a Healthy Kentucky estimates more than 40,000 Kentuckians will no longer get help paying for their insurance. According to Beshear, 88,000 Kentuckians bought insurance through the federal exchange and the federal government's action will cause rates rise by nearly 20%.

"Kentuckians face numerous health issues, and our communities are facing the worst drug epidemic our nation has ever seen. Access to affordable health care and drug treatment will move Kentucky forward. It is one of our best hopes. Now is not the time to turn our backs on hard-working Kentuckians," said Beshear.