Michael Bloomberg, billionaire and former mayor of New York, appears at a global city summit in Detroit on Oct. 29. (Bill Pugliano/Getty Images)

Former New York mayor Michael R. Bloomberg announced Sunday he is giving a record $1.8 billion to Johns Hopkins University to support student financial aid at his alma mater and make its admissions process “forever need-blind.”

The gift, believed to be the largest private donation in modern times to higher education, is a landmark in a growing national movement to make elite universities more accessible to students from low- to middle-income families.

It will enable the private research university in Baltimore to eliminate loans from financial aid packages for incoming students starting next fall, expand grants for those in financial need and provide relief to many current undergraduates who had previously taken out federal loans to pay their bills.

In years past, Hopkins President Ronald J. Daniels said, the university struggled to achieve its goal of welcoming all talented students regardless of their means or backgrounds.

“Our dedicated financial aid endowment was simply too small,” Daniels said. “Now, as a consequence of Mike Bloomberg’s extraordinary gift, we will be fully and permanently need-blind in our admissions and be able to substantially enrich the level of direct assistance we provide to our undergraduate students and their families.”

Bloomberg, who graduated from Hopkins in 1964, wrote in an op-ed for the New York Times that his gift is intended to support the idea that opportunities should be based on merit and not wealth. “This will make admissions at Hopkins forever need-blind; finances will never again factor into decisions,” he wrote.

With the donation, the 76-year-old businessman and politician underscored his philanthropic commitment at a moment when he is mulling a run for the presidency in 2020 as a Democrat. (He also has been a Republican and an independent in his political career.) Bloomberg had given $6.4 billion to education and other causes before Sunday’s announcement.

Now, his total lifetime giving to Hopkins alone will exceed $3.3 billion.

The gift will reverberate throughout higher education as selective colleges and universities seek financial resources that will enable them to recruit more students from lower- and middle-income families. Direct aid from colleges is crucial because the maximum federal Pell Grant provides $6,095 a year for students in need, less than a tenth of what many selective private schools charge for tuition, fees, and room and board. Some, including Hopkins, charge $70,000 a year.

Bloomberg’s gift will help Hopkins make up the difference, and it challenges others to do the same for colleges elsewhere.

“What he’s raising here is a call to action across the board, to institutions, to donors and particularly to policymakers to make sure that American higher education is an engine of social mobility,” said Ted Mitchell, president of the American Council on Education, which represents colleges and universities.

“This is a very, very big gift in all capital letters,” Mitchell said. “A remarkable gift in many ways.” Often, major gifts focus on endowing faculty positions or building laboratories and classrooms. This one is endowing aid.

“This isn’t about buildings, the university bureaucracy or anything else,” said Jon Schnur, an adviser to Bloomberg on education. “It’s all about directly supporting these students.”

Comparing donations across eras is difficult. Inflation calculators show the $7 million bequest from Johns Hopkins in 1873 that established the namesake university would be worth far more than $100 million today.

The Chronicle of Higher Education tracks major donations to higher education since 1967. Two $1 billion gifts top that list: A 1999 pledge from the Bill and Melinda Gates Foundation for a program called Gates Millennium Scholars and a 2006 pledge from the Anil Agarwal Foundation to establish Vedanta University in India.

Now, Bloomberg has eclipsed that mark. It’s the latest in a series that started with a $5 donation to Hopkins the year after he graduated.

Bloomberg in recent years has championed an initiative to secure pledges from selective colleges to add tens of thousands of low- to moderate-income students to their rolls. More federal and state funding, he said, will be crucial for achieving that goal. He also has financed efforts to provide those students with more effective college counseling.

For Hopkins, the latest gift is a milestone in a several-year effort to diversify its student body. The university has about 25,000 students, federal data show, including roughly 6,000 undergraduates. It enrolls about 1,300 freshmen a year to its main campus in Baltimore.

This year, about 15 percent of freshmen qualify for Pell Grants. Through Bloomberg’s gift — to be distributed “essentially immediately,” according to a Bloomberg aide — Hopkins plans to take steps to raise that share to at least 20 percent. It also will advertise widely for the first time that its highly competitive admissions process is “need-blind” — meaning that financial circumstances are not taken into account as the school chooses a class. And it will advertise that it will meet the full financial need of the students it admits, without asking them to take out loans.

That formulation — need-blind, meeting full need, omitting loans from aid packages — is the gold standard for accessibility in college admissions. U.S. News & World Report counts only 18 wealthy institutions, including six in the Ivy League, that are able to reach it.

For the past eight years, Hopkins quietly held to a need-blind policy in admissions, Daniels said. But it has been reluctant to advertise that policy because of the fear that it might have to pull back from the promise.

“The truth of the matter was that our program was really being held together with spit and bubble gum,” Daniels said. “Now, we’re obviously in a very different place.”

Daniel Porterfield, a former college president who is president and chief executive of the Aspen Institute, said Bloomberg’s gift raises the bar for schools in the Ivy League and elsewhere because it establishes a promise of full access in the future.

“Now they’ll have to ask themselves: Can they also make that commitment in perpetuity?” Porterfield said.