The University of Massachusetts system, the third-largest employer in the state, will cut about six percent of its full-time equivalent workforce and furlough thousands as part of its efforts to close a $264 million budget gap ripped open by the COVID-19 pandemic.

Nearly three in 10 UMass employees will be affected by the cost-saving measures, and university officials will also scale back spending on supplies and capital projects.

At a virtual meeting Monday where the board of trustees approved a $3.3 billion fiscal 2021 budget that freezes tuition, President Marty Meehan warned that the four campuses and medical school must overcome an “unprecedented financial challenge.’

He added, “we face difficult decisions today and we will continue to face them in the weeks and months ahead. We are coming at this problem from every possible direction.”

Officials cut workforce spending by about $163 million and non-personnel costs by $92 million to help balance the budget, according to a summary provided by a spokesperson.

The system has already laid off 134 of its nearly 24,000 workers and will terminate employment of another 397. In addition, about 1,125 student and temporary positions have also been cut; 790 open full-time equivalent jobs will not be filled; and more than 3,000 employees face furloughs this fiscal year, according to the summary.

About $243 million in planned long-term capital projects are on hold across the UMass system. Other savings will come from consolidating procurement for the multiple schools and continuing a years-long efficiency effort.

Planning for the upcoming year is made more challenging by uncertainty about federal legislative action and enormous budget strains on state government. In Massachusetts, officials project a revenue shortfall of $2 billion to $8 billion below earlier estimates, and state leaders have yet to fashion a plan to deal with that.

Other questions linger about the number of students who will remain enrolled once their schools shift to mostly or entirely online classes. UMass campus officials anticipate a decline in enrollment of about five percent, but said Monday that number could change as the fall semester approaches.

The fiscal 2021 budget UMass trustees approved Monday, which is about $171 million less than fiscal year 2020’s spending levels, also responds to the outbreak by planning for additional precautions and aiming relief at students and their families.

Campuses will collectively spend about $30 million more on testing, personal protective equipment, physical distancing preparations, and other precautions against transmission of the highly infectious virus.

Meehan praised UMass for confronting the COVID crisis “better than many.”

With Monday’s vote, trustees gave their approval to a plan Meehan unveiled in May to freeze tuition for nearly 48,000 in-state undergraduates and 9,500 graduate students across the Amherst, Boston, Dartmouth, and Lowell schools.

Officials had increased tuition annually to mirror inflation for the past several years, but it will remain at last year’s level for the 2020-2021 academic year. That change means UMass will forego about $18.6 million in revenue for the system next year.

“Freezing tuition is the right thing to do, but will put additional stress on our budgets,” Meehan said.

UMass anticipates its student population will receive almost $1 billion in financial aid from a combination of federal, state, private, and university sources in fiscal year 2021.

The board approved both the fiscal 2021 budget and the tuition freeze unanimously, with trustees Stephen Karam and Julie Ramos Gagliardi abstaining from the student fees question.

UMass labor representatives flagged concerns with the plans during Monday’s call, urging campus leaders to embrace more defined plans for providing personal protective equipment and cleaning and to seek alternate ways to balance the budget rather than imposing cuts.

Anneta Argyres, who directs UMass Boston’s Labor Extension Program and is the president of the Professional Staff Union for the Boston and Amherst campuses, told the board her 2,000-member union is “very concerned” about the positions that will be lost, arguing that online learning requires more teaching and support staff than in-person instruction.

“This is not the time to eliminate jobs in public higher education, but jobs are being eliminated across our campuses,” Argyres said.