But Harvard is not immune to such a rapid and unprecedented cutoff of the kind of research dollars that comprise at least one-tenth of its annual revenue.

Last week, days after a list of demands from Trump’s antisemitism task force arrived, Harvard geared up to increase its short-term borrowing and bolster cash reserves. And after Monday’s notice from Washington, a top Harvard scientist is readying herself to kill the animals used in research that will lose funding, while university departments are advising researchers “to make plans immediately for the possible imminent termination of all federal funds,” STAT reported.

It begs the question: How will Harvard tap its financial resources to maintain business-as-usual— at least to the extent possible — amid a full-frontal financial assault? And what other parts of the university budget are in the line of sight of the Trump administration?

Harvard leans heavily on its $53.2 billion endowment to supplement donations, tuition, and outside grants in its annual budget.

The school often points out that that money is not just in a bank account it can tap at any time. Around 80 percent of the endowment is restricted by its donors for use on financial aid, predetermined professorships, and specific fields of academic study, according to Harvard’s financial report. Nearly one-third of the budget for the Kennedy School, for example, is from gifts reserved for current use — money that cannot be transferred to a different part of the institution.

“You can’t just reach your hand into the endowment and pull funds out,” said Phil Levine, a professor of economics at Wellesley College. “Using it as a piggy bank is not allowed.”

That said, the Harvard Corporation — a small but mighty governing board that manages university finances— allocates a percentage of the endowment returns each year toward the university’s operating budget, typically based on investment performance. Most years, that distribution comes to between 5 and 5.5 percent of the total endowment; it has topped 6 percent just once since 2007 — in 2010, when the college was recovering from the global financial crisis.

Still, the endowment allocation makes up a huge chunk of Harvard’s annual budget. It accounted for 40 percent of the $6.5 billion Harvard spent last fiscal year, and comprises the bulk of the budget at the Radcliffe Institute, Divinity School, and the Faculty of Arts and Sciences, which includes its undergraduate and PhD programs.

The endowment has so far been untouched by the White House, which has focused efforts on the money that flows from the federal government to academic research. But Republicans in Congress have floated the prospect of hiking taxes on large endowments tenfold from 1.4 to 14 percent, an increase that would hit Harvard — whose endowment is larger than the gross domestic product of Iceland or Bahrain — harder than anyone.

There are market threats, too. Harvard’s endowment fund grew nearly 10 percent last year because of an uptick in the stock market, but the landscape for both stocks and bonds has turned volatile after Trump enacted new tariff policies that some warn will cause a recession. That may affect the returns Harvard sees on the fund next year.

Harvard’s endowment also hinges on donors. The tumult of last year — marked by student protests over the war in Gaza and a leadership change after former president Claudine Gay was ousted — led to “disappointing” fund-raising numbers, college officials said, and a $1.4 billion, or 15 percent drop, in total gifts.

It is yet to be seen how donors will respond to Harvard’s aggressive response to White House demands, though the move has drawn praise from students, faculty, and prominent Democrats.

Endowment aside, it’s expensive to run an elite institution like Harvard.

The revenue Harvard collects from tuition, food services, and housing grew this past fiscal year, contributing to $6.5 billion in revenue, financial reports show. But Harvard’s expenses are growing 3 percent faster, a trend the university attributes to inflation and increased employee hiring. In all, Harvard has almost 25,000 students.

The programs potentially facingthe most duress are those that receive the most “sponsored support” — funding from external sources, including government agencies, private companies, and other organizations. Harvard’s public health and engineering schools generated 59 and 37 percent of their annual operating revenue, respectively, from such support last year, while Harvard Medical School relied on outside funding for 35 percent of its budget.

Dr. Neal Baer, a Harvard Medical School lecturer, said his department — social medicine — is planning for 15 percent budget cuts by slashing extraneous expenses while trying to maintain teaching quality and the typical size of the graduate student class. The medical school’s longstanding reliance on federal funding is “not a bad thing,” Baer said.

“But it’s time to think of new partnerships and new ways of working with a variety of parties with an interest in promoting health and well-being,” he said. “If that is not going to be the federal government right now, then we will find other sources.”

Altogether, research funding at Harvard makes up a larger slice of the university’s revenue than tuition from degree-seeking students. (Harvard has one of the most expensive undergraduate tuition sticker prices in the country, at around $85,000 annually.)

In 2024, 21 percent of operating revenue at Harvard came from educational programs — both degree-seeking and continuing education. It’s unclear howthe school’s pledge to go tuition-free for families with incomes below $200,000 a year could impact that sum, or if applications from international students will decline as the Trump administration targets visa protections and legal status for foreign students.

Students from other countries are far more likely to pay the full cost of tuition and balance tuition calculations for Harvard, which offers significant subsidies to low-income students.

Harvard still has more liquid assets than a typical institution and can tapbillions in bank credit and short-term borrowing to sustain itself, said Sally Bednar, a college consultant and the former head of the higher education team at Wells Fargo. And because the funding being frozen was intended to be paid out over the next few years, Bednar added, the university may not institute cuts immediately.

“Harvard has access to many bank facilities and commercial paper lines,” Bednar said. “The hard cuts would likely not be this fiscal year, but the following year.”

This is not the first time Harvard has faced a tough financial picture. In the aftermath of the global financial crisis and during the COVID-19 pandemic, the university enacted cuts that could offer a blueprint for what may happen this time.

In the aftermath of the 2008 recession, Harvard’s endowment declined by almost 30 percent, forcing the university to issue $2.5 billion in bonds and increase its debt load. College officials trimmed the Faculty of Arts and Sciences budget by $77 million, froze salary raises for faculty, and put tenure-track hiring on hold. The university also paused construction on its massive Allston campus and even temporarily eliminated hot breakfast for students.

In 2020, with more “recession-based scenario planning” to lean on, Harvard similarly paused hiring and raises, but avoided the layoffs that other schools had to enact. More liquidity in the budget gave the college room to sustain costs from COVID safety precautions and even increase undergraduate financial aid.

The moment is different now, when impending financial challenges for Harvard are promptedlargelyby a sustained attack from powerful politicians.

Harvard froze hiring last month due to initial threats to federal research funding, but has taken no public steps since to curtail campus expenses during the $9 billion financial “review” from the White House.

In its most recent financial report, released in October, Harvard reported that its ongoing construction projects — including the Allston campus project, American Repertory Theater construction, and student housing developments — were on “terra firma.”

How long that will last remains to be seen.

Diti Kohli can be reached at diti.kohli@globe.com. Follow her @ditikohli_.