KEY POINTS
  • Epic Systems told customers in a notice on Thursday that the company cut off data access to a startup called Particle Health.
  • Epic said Particle was sharing patient data with companies that were using the information for reasons having nothing to do with treatment.
  • "This poses potential security and privacy risks, including the potential for HIPAA Privacy Rule violations," Epic said in the notice, which was obtained by CNBC. 
The eponymous sign outside Epic headquarters in Verona, Wisconsin.

Epic Systems, the largest provider of software for managing medical records, says a venture-backed startup called Particle Health is using patient data in unauthorized and unethical ways that have nothing to do with treatment.

Epic told customers in a notice on Thursday that it cut off its connection to Particle, hindering the company's ability to tap a system with more than 300 million patient records. Particle is one of several companies that acts as a sort of middleman between Epic and the organizations — typically hospitals and clinics — that need the data.