Change Healthcare to start notifying customers who had data exposed in cyberattack

Change Healthcare is starting to notify hospitals, insurers and other customers that they may have had patient information exposed in a massive cyberattack.

The company also said Thursday that it expects to begin notifying individuals or patients in late July.

Change Healthcare, a subsidiary of health care giant UnitedHealth Group, provides technology used to submit and process billions of insurance claims a year. Hackers gained access in February to its system and unleashed a ransomware attack that encrypted and froze large parts of it.

The attack triggered a disruption of payment and claims processing around the country, stressing doctor’s offices and health care systems by interfering with their ability to file claims and get paid.