A Trump-appointed federal judge has blocked a key rule that would have removed medical debt from the credit reports of 15 million Americans, leaving millions of Americans vulnerable to financial ruin.

U.S. District Court Judge Sean Jordan of Texas removed a Biden-era finalized rule by the Consumer Financial Protection Bureau that would have removed medical debt from credit reports.

A federal judge vacated a Biden-era rule that would've banned medical debt on credit reports — but protections remain under ...