The Trump administration is terminating the jobs of dozens of technology specialists whose broad portfolio of projects across the government included the I.R.S.’s free tax filing software and passport services.

The specialists, who belonged to a unit at the General Services Administration known as 18F, developed software and technology products for various federal agencies, with the goal of improving efficiency and better serving the public. In an email to workers at the agency’s Technology Transformation Services over the weekend, Thomas Shedd, a former Tesla engineer who is now the division’s director, said that 18F had been identified as noncritical and would be cut.

“This decision was made with explicit direction from the top levels of leadership within both the administration and G.S.A.,” Mr. Shedd said in the email, a copy of which was obtained by The New York Times. He added that while no other Technology Transformation Services programs had been affected, “we anticipate more change in the future.”

In termination letters dated Friday, employees were informed that their roles would be eliminated in keeping with President Trump’s orders to downsize the government. Workers have been placed on administrative leave until they are officially released at the end of April, according to copies of letters seen by The New York Times.

A spokeswoman for the G.S.A. said in a statement that the administration would continue to embrace technology that would enhance and modernize the government’s digital infrastructure and I.T. capabilities, in a statement confirming that employees of 18F had been informed they would be laid off.

Among the marquee websites that 18F employees helped build or revamp are the Internal Revenue Service’s free tax filing service known as Direct File and the National Weather Service’s page, weather.gov.

But since Mr. Trump returned to the Oval Office, 18F has also been targeted by Elon Musk, the tech billionaire whom Mr. Trump tasked with cutting back the government. Mr. Musk wrote last month in a post on his social media platform, X, that “that group has been deleted.”

The Obama administration created 18F and the U.S. Digital Service in 2014 to help agencies develop and integrate digital software, after its faulty rollout of healthcare.gov, which crashed on the first day consumers were eligible to purchase health care plans through insurance exchanges. The new offices were envisioned as in-house technology consulting firms, with the goal of managing costs and improving efficiency of the government’s digital offerings.

The U.S. Digital Service was one of the earliest corners of the government to get a Musk makeover, when Mr. Trump renamed it the U.S. DOGE Service — the operation that Mr. Musk has used to slash contracts and pressure government employees to resign.

Within hours of receiving Mr. Shedd’s notice on Saturday, employees of 18F created a website to air their grievances against the Trump administration and accuse higher-ups of undermining an operation they had praised just weeks before.

The 18F employees cited an internal meeting in early February in which Mr. Shedd, they said, had “acknowledged that the group is the ‘gold standard’ of civic technologists,” and “repeatedly emphasized the importance of the work, and the value of the talent that the teams bring to government.”

Their work had been halted so abruptly, the suspended employees continued, that they were unable to assist in an orderly transition or even learn where to return their equipment. Before their suspensions, the website continued, 18F staff were working to help the I.R.S. support free filing software, to improve access to weather data at the National Oceanic and Atmospheric Administration, and streamline the process of procuring a passport.