Note text below "saying a federal court ruling ties its hands" meaning this is a mandatory order from the court not an elective action from the Trump administration. They could have titled it as the courts froze collecting or making payments ... less sensational but more accurate.

Trump Freezes Billions In Obamacare Payments, Outraging Insurers

"The Trump administration halted billions of dollars in payments to health insurers after the Centers for Medicare and Medicaid Services, the agency that administers programs under Obamacare, announced on Saturday it was freezing payments to insurers that cover sicker patients, saying a federal court ruling ties its hands. ...."

"......The CMS, which is part of the Department of Health and Human Services, added that the court’s ruling bars the agency from collecting or making payments under the current methodology, which uses a statewide average premium, Bloomberg reported.

“We were disappointed by the court’s recent ruling. As a result of this litigation, billions of dollars in risk adjustment payments and collections are now on hold."  CMS Administrator Seema Verma said in the agency’s statement......"

https://www.zerohedge.com/news/2018-07-08/trump-freezes-billions-obamacare-payments-outraging-insurers