WASHINGTON, DC: The U.S. Federal Trade Commission is investigating healthcare database giant Epic Systems over how it grants or restricts access to health data, according to two sources familiar with the matter.

The privately held company operates electronic health record systems used by hospitals and clinics across the United States, including the patient web portal MyChart. Healthcare providers using Epic's products collectively treat more than 280 million people in the U.S., according to the company's website.

As part of its antitrust investigation, the FTC has sent investigative demands to others in the health technology industry seeking information about how Verona, Wisconsin-based Epic grants or withholds access to data, the sources said.

"We're leaders in interoperability to support patient care, and we do not engage in anticompetitive behavior," an Epic spokesperson said when asked about the investigation.

An FTC spokesperson declined to comment.

Epic also operates a research platform that allows health systems that have opted in to conduct research using data from 310 million patients, according to the company's website.

The FTC investigation comes as Epic faces separate allegations that its business practices restrict competition.

Texas Attorney General Ken Paxton sued the company in December, accusing it of shutting out would-be rivals by holding data hostage. The state alleges Epic uses restrictions and fees to prevent healthcare systems from using competitors.

Epic has denied those claims. The company says its products are interoperable with outside systems and that its healthcare provider customers, rather than Epic itself, control access to patient records.

Particle Health has also previously sued Epic. Particle competes with the company in the market for platforms that insurers use to review and store medical records on a large scale.

In its lawsuit, Particle accused Epic of creating barriers for potential new Particle clients.

Epic has called Particle's lawsuit baseless and said the company obtained confidential patient medical records under false pretenses. Particle has denied that allegation.