WASHINGTON — Federal agencies faced a deadline Monday to present their plans for another round of mass firings, the next step in the Trump administration’s drive to shrink the government that figures to further reshape a civil service that has endured tens of thousands of departures.

Some agencies, such as the Department of Health and Human Services, have already announced their layoffs for this round of dismissals, which follows the terminations in February of thousands of probationary federal employees. The cuts have come at the direction of the Department of Government Efficiency, the overhaul initiative led by tech billionaire Elon Musk.

The group’s hard-charging effort has cast a pall over the federal workforce since Trump returned to the Oval Office. This week’s plans for the mass firings, called “reductions in force,” should offer a clearer picture of the administration’s vision of a downsized federal government.

Thousands of workers have also resigned voluntarily in recent days, accepting an offer to quit while temporarily being paid — including more than 1,100 people at the National Park Service, according to a person familiar with the details. The incentive applied only in certain departments as the deadline neared and was originally pitched in January as a one-time offer.

Since Jan. 20, agency supervisors and managers have largely been left in the dark about the personnel changes. Many have come to rely on the news media to learn about their job security, a scientist with the Environmental Protection Agency said.

Scant information about the resignation and early retirement offers has left federal workers to seek advice on social media about whether to accept.

On April 7, the Department of Homeland Security sent an email announcing that it would also be offering another shot at deferred resignation and early retirement. The message said human resources officials would follow up with more details.

But one official said that never happened, giving him just 48 hours to give the department his decision.

The thousands of fired probationary workers have been in a state of limbo since mid-February, with court rulings that forced the government to reinstate the employees that have since been overturned or paused.

Some fired workers who returned to their jobs this month have not been able to get a clear answer from their human resources officials about whether they were eligible for a deferred resignation or if their employment status had changed.