Democratic lawmakers are demanding that the Trump administration halt plans to collect sensitive medical records for millions of federal workers and retirees, as well as their family members.

The Office of Personnel Management has asked 65 insurance companies to provide monthly reports with detailed medical and pharmaceutical claims data of more than 8 million people enrolled in federal health plans, KFF Health News reported earlier this month. The request, which could dramatically expand the personally identifiable medical information OPM can access, alarmed health ethicists, insurance company executives, and privacy advocates.

Now, OPM Director Scott Kupor has two letters on his desk — one from 16 U.S. senators and another led by Rep. Robert Garcia, the top Democrat on the House Oversight Committee — asking him to drop the agency's proposal.

"The collection of broad, personally identifiable data regarding medical care and treatment raises concerns that OPM could target certain federal employees seeking vital health care services that the Administration disagrees with on political grounds," the Democratic House members wrote to Kupor April 17, citing KFF Health News.

The letters from congressional Democrats alone are unlikely to reverse OPM's plans. Republicans — who control Congress and, ultimately, any oversight activities — have not weighed in on OPM's notice.

OPM did not immediately respond to a request for comment on the letters. The agency, which said in its notice that it will use the data for oversight and to manage the federal health plans, has not publicly addressed written concerns about its proposal.

The notice, posted and sent to insurers in December, states that insurers are legally permitted to disclose "protected health information" to OPM and does not provide instructions to redact identifying information, such as names or diagnoses, from the claims.

That data could be used to implement cost-saving measures, health policy experts told KFF Health News earlier this month. But it would also give the Trump administration — which has laid off or fired tens of thousands of federal workers — access to a vast trove of personal information.

In the letters, Democratic lawmakers lay out a number of concerns about potential consequences of OPM's obtaining detailed medical claims for millions of federal workers.

The letter from Senate Democrats — led by Adam Schiff of California and Mark Warner of Virginia — argues that OPM is not equipped to safeguard such sensitive data and that the administration could share the records across government agencies, as it has done with personal information on millions of Medicaid enrollees.

They also assert that the agency does not have a legal right to the data and that insurers' sharing the information with OPM would "violate the core principles of the Health Insurance Portability and Accountability Act." HIPAA requires certain organizations that maintain identifiable health information — such as hospitals and insurers — to protect it from being disclosed without patient consent. The proposal, the senators warn, threatens patients' relationships with their clinicians, especially "sensitive disclosures regarding mental health, chronic illness, or other deeply personal conditions."

"For these reasons, we strongly urge you to cease any further consideration of this proposal," states the letter, which was sent to Kupor on April 19.

The American Federation of Government Employees, the largest union for federal employees, responded with alarm to KFF Health News' reporting. The union noted in a statement from its national president, Everett Kelley, that OPM's proposal "comes in the context of coordinated attacks on federal employees and repeated stretching of the legal boundaries for sharing sensitive personal data across government agencies.

"The question of what this administration intends to do with eight million Americans' most private health information is not academic," the AFGE statement read. "It is urgent."

In an emailed statement, Kelley applauded the congressional letters.

"We are pleased that Democratic lawmakers on the Hill are just as outraged as we are over this administration's blatant attempt to breach the privacy of millions of Americans across the country," Kelley wrote. "We share their concerns regarding potential misuse of the information to continue illegally targeting workers and their demand for OPM to withdraw this proposal."

KFF Health News is a national newsroom that produces in-depth journalism about health issues and is one of the core operating programs at KFF — the independent source for health policy research, polling, and journalism.