Most of the nation’s 2.1 million federal employees will report to work Monday to tightly packed office cubicles and other workplaces where they serve the public, even as schools and colleges across the country have closed, businesses have sent their staffs home to work and governors have canceled public activities to limit the spread of the coronavirus.

Top U.S. health officials are urging Americans to limit close contact with others, but the federal government appears to be hunkering down to limit disruption, creating widespread anxiety for employees who fear they are putting themselves and their families at risk.

Sunday night, in response to mounting criticism, the Trump administration urged agencies in the Washington area to “offer maximum telework flexibilities” to employees who are eligible for remote work.

The guidance followed a recommendation from the acting White House budget director Friday that limited telework to the elderly, pregnant or those with health risks. But Sunday’s directive was not mandatory, and it left out most of the government. Just 15 percent of the federal workforce is in the D.C. area.

It did not make allowances for Lauri Dahlem, a legal assistant at the Social Security Administration’s disability hearings office in Lansing, Mich., who prepares cases for administrative judges.

Her work can all be done electronically, she said. And with a husband recovering from complications from a stem cell transplant to treat lymphoma, she asked to telework. She is worried about infecting him. She said the answer was no.

“My supervisor said I was exempted because I’m only taking care of someone who’s sick,” ­Dahlem, an Army veteran and former military police officer, said Sunday. “I want to work. I’m a very capable worker. It’s insane.” As of Friday, the eight administrative law judges in her office were still hearing cases face to face.

The government’s pandemic response has left many government managers and their staffs on edge.

Snow days are cut and dried — operations slow for a day or two. A shutdown has defined contours — who can work and who can’t and which services can’t continue as a result. But the coronavirus strategy feels to many workers like a slow-roll to a precipice.

“Asking employees to work like this has never been done before,” said Daniel Kaniewski, who until February was the Federal Emergency Management Agency’s second-ranking official. “Can you do the functions of government at home on this scope and for an extended duration?”

Dozens of federal employees have tested positive for the virus, including at Veterans Affairs hospitals and Department of Homeland Security offices. Their cases have led a few agencies, including the Securities and Exchange Commission, NASA and the Environmental Protection Agency, to send some offices’ employees home to telework.

Agencies have shifted to pandemic footing — at the edges. They are limited to “mission-critical” travel. The Pentagon has canceled public tours. NASA, the Federal Aviation Administration and others have stress-tested their computer networks to see whether they can handle the load of so many employees dialing in at once. (Connections were slow.)

The State Department has authorized its overseas staffers who face high medical risks to fly home. Offices are shifting to rotating schedules, to limit contact and network use.

But as of Friday, the Trump administration had allowed relatively few employees to work from home, after announcing weeks ago that it was preparing them to rely heavily on telework to continue operations in a pandemic.

“Every agency is scared to death to do anything without getting approval, and they don’t want to be first,” said one senior manager, who like others spoke on the condition of anonymity because he was not authorized to discuss coronavirus preparations.

More than 40 percent of the federal workforce was eligible for telework when President Trump took office in 2017. Then the administration scaled back working from home as a regular practice at multiple large agencies, complicating a quick ramp-up now.

A spokesperson for the Office of Management and Budget said in an email Sunday, “The Federal government is encouraging agencies to exercise maximum telework flexibilities for their employees while still allowing for mission critical activities to continue.”

A few agency leaders have acted decisively. But others say they are waiting for more direction from the budget office, which is in transition with the departure of its top official overseeing federal operations. On one hand, they have been told to decide on their own how much telework to authorize. On the other, the budget office must approve any big shift to remote work. “The White House is not set up to micromanage operations like this,” said a senior agency manager. “It takes too long.”

The result is chaos and a sense of paralysis in some offices as coronavirus caseloads mount.

Telework on such a sustained scale would be unprecedented for the government, but it has the potential to keep many operations going, such as court hearings and addressing tax questions. The fate of public-facing functions, such as meat inspection, postal delivery and passport processing, is unclear.

The White House has instructed agencies to update continuity-of-operations plans they last prepared with the influenza virus known as H1N1 in 2009, laying out how they would pare down to essential services with skeletal staffs. They are still waiting to be deployed, with an unclear trigger for when the White House would take action.

Federal managers say they are struggling to figure out what comes next for their staffs and their mission.

“This is of a shutdown magnitude, but it doesn’t have clear lines like a shutdown,” said Mark Greenblatt, the Interior Department inspector general, who last week told his 265 auditors and investigators they could telework.

“With a shutdown, the light switch is on, or it’s off,” he said. “This is rapidly unfolding and uneven. It’s regional. Different populations are more vulnerable.”

On the OMB’s daily call Sunday with senior leaders from major agencies, officials ticked through the number of confirmed or suspected coronavirus cases on their staffs. They described which field offices they were having cleaned after employees tested positive.

An Interior Department official asked how to convey safe health practices between their employees and the public they serve at tourist sites. A Social Security Administration leader said school closures are starting to affect field offices that serve the public and warned that “at some point” walk-in service and regular office hours would be impossible because of employee absences. But there was little sense of when the public health crisis would or should lead government leaders to move to more of an emergency footing.

“We’re seeing agency after agency not release people” to work from home, said David Cann, director of field services and education at the American Federation of Government Employees, the largest union representing federal workers. “If I’m a manager who is a jerk, or disengaged, they’re saying, ‘I’m not going to do it.’ ”

The Department of Housing and Urban Development has not provided its staff with uniform guidance on telework, with each office adopting its own policies. Some employees say they want concrete instructions to work from home for a period of time, rather than just being told to be “telework ready.”

HUD Secretary Ben Carson told staffers in an email Friday that they are “still expected to continue working at their assigned duty station or via telework, if approved by their supervisor.”

“We encourage staff to discuss offered workplace flexibilities with your supervisor such as telework, leave, schedule adjustments, alternative work locations, etc.,” he wrote.

The Internal Revenue Service, weeks away from the April 15 tax filing deadline, is still operating normally, although call centers are seeing a surge from anxious taxpayers wanting to know how soon they will get their refunds.

IRS Commissioner Charles Rettig had said little to managers about the telework policy until an email at 8:15 p.m. Friday, which suggested that front-line field offices staffed by thousands of employees should have the option to avoid “all in-person contacts.”

But it was unclear how that would be accomplished without large absences. A fraction of call-center employees are authorized to answer phones from home.

Airline operations are continuing for now, but there are signs of stress. The FAA said that service levels might dip if emergency plans are deployed but that it would guarantee safety.

Traffic can be routed through different parts of the skies if there are not enough controllers in one particular area, or planes could be kept on the ground altogether. With passengers canceling flights in droves and airlines announcing reductions in service, the number of planes in the air is expected to be lower than usual.

The Transportation Security Administration is already dealing with absences. When a handful of TSA officers at Mineta San Jose International Airport were diagnosed with the virus, there was a ripple effect. Initially only three officers tested positive, but James Mudrock, a local TSA union official, said 42 were placed under quarantine. That meant the airport was down about 10 percent of its security screening workforce.

So far, Mudrock said, that had not affected wait times or security, but if more officers were out of work, it could. On Friday, the agency confirmed that a fourth officer at the airport had been diagnosed with the coronavirus.

Mudrock said local managers were working hard to keep operations going but said information about any continuity planning had yet to reach his level. “There’s still a lot of planning that needs to be done,” he said.

A TSA spokeswoman did not respond to questions about the agency’s continuity planning. But an official who requested anonymity said that with large numbers of officers out, there would be little option other than to close some security gates.

“If we stop showing up for work, planes aren’t going to fly,” the official said.

John Hudson, Michael Laris, Renae Merle, Missy Ryan and Matt Zapotosky contributed to this report.