Thousands of Agriculture Department employees who were fired last month must be reinstated in their old positions for at least 45 days, a board that handles federal worker disputes ordered on Wednesday.

The fired employees were on probationary status and relatively new in their positions, swept up in the Trump administration’s push to rapidly reduce the size of the federal work force in part by targeting those types of workers. Probationary employees have fewer Civil Service protections than other government workers who have been in their jobs longer, and have been seen by President Trump and Elon Musk, the tech billionaire leading the downsizing effort, as the easiest to fire.

Even so, there are rules that agencies must follow when firing probationary employees, including a requirement that managers document details when alleging poor performance.

Cathy Harris, the chair of the Merit Systems Protection Board, the administrative body where employees can appeal adverse actions, said in her order on Wednesday that she had “reasonable grounds” to believe that agencies that had fired probationary workers violated a law that dictates proper personnel practices.

Currently, the board’s decision applies only to probationary employees at the Agriculture Department who were fired on Feb. 13, estimated to be 5,000 to 6,000 people.

The department did not immediately respond to a request for comment.

The order signals that the board could rule in favor of other fired probationary employees if the Office of Special Counsel, which brought the Agriculture Department case forward, produces similar evidence that other agencies violated personnel laws as well.