U.S. Postal Service and other investigators are probing who fraudulently filled out a change-of-address form for Citizens Property Insurance, causing checks for payment from policyholders in June to go to a Hialeah, Fla., apartment, not the state’s property insurer of last resort.

Two Illinois doctors and a billing employee were indicted on federal health care fraud charges, accused of submitting false claims of more than $1 million to obtain payments from insurers for services never provided and for inflating claims for work they did perform.