US officials say they have blocked or recovered more than $1.6 billion in potentially improper Medicare payments to laboratories since President Trump returned to office. The action is intended to protect the Medicare Trust Fund by identifying suspected fraud before payments are made, including claims for tests allegedly never performed, medically unnecessary tests and inflated charges.

The Centers for Medicare and Medicaid Services said $732 million involved 157 laboratory providers removed from Medicare over alleged fraud, while more than $500 million was prevented through 185 payment suspensions following investigations into 600 labs. The agency also recovered $276 million in overpayments from 442 suspect labs and referred 85 cases to law enforcement, preventing a further $127 million; it says artificial intelligence is being used to detect unusual billing patterns.