At the National Institutes of Health, six directors — from institutes focused on infectious disease, child health, nursing research and the human genome — are leaving or being forced out.

At the Federal Aviation Administration, nearly a dozen top leaders, including the chief air traffic officer, are retiring early.

And at the Treasury Department, more than 200 experienced managers and highly skilled technical experts who help run the government’s financial systems chose to accept the Trump administration’s resignation offer earlier this year, according to a staffer and documents obtained by The Washington Post.

Across the federal government, a push for early retirement and voluntary separation is fueling a voluntary exodus of experienced, knowledgeable staffers unlike anything in living memory, according to interviews with 18 employees across 10 agencies and records reviewed by The Post. Other leaders with decades of service are being dismissed as the administration eliminates full offices or divisions at a time.

The first resignation offer, sent in January, saw 75,000 workers across government agree to quit and keep drawing pay through September, the administration has said. But a second round, rolling out agency by agency through the spring, is seeing a sustained, swelling uptick that will dwarf the first, potentially climbing into the hundreds of thousands, the employees and the records show.