Western Michigan University, usually overshadowed by certain other state schools in Ann Arbor and East Lansing, announced Tuesday that it has landed the largest private gift ever to a public university: $550 million.

The blockbuster donation to the university in Kalamazoo, from anonymous Western Michigan alumni, eclipses the previous record of $500 million on a list kept by the Chronicle of Higher Education.

The funding, to be delivered to the university’s foundation over 10 years, will flow in three main streams: $300 million for Western Michigan’s Homer Stryker M.D. School of Medicine; $200 million for need-based financial aid, faculty hiring and other university initiatives; and $50 million for the school’s Bronco athletic programs.

Often, major donations help the richest colleges and universities get richer. That is not the case in this instance. Western Michigan’s endowment, before the gift, stood at $480 million, school officials say. That is a substantial sum but far lower than the holdings of the state’s two most prominent universities.

Michigan State University, in East Lansing, and its foundation held a total endowment of about $3.4 billion in 2020, according to the National Association of College and University Business Officers. The University of Michigan, with the state flagship campus in Ann Arbor, reported a $12.5 billion endowment.

The new donation represents a coup for Western Michigan.

“We do a good job in promoting social mobility,” university president Edward Montgomery said in a telephone interview. “Our donors believe in that vision. ... I’m immensely pleased to have this gift. Its size allows it to be transformative.”

The president said the gift will allow the university to make education more affordable for underrepresented groups of students.

Montgomery described the donors as “longtime supporters of the university who have always been advocates for social justice and the advancement mission of the campus.”

Founded in 1903 with the mission of preparing schoolteachers, Western Michigan became a university in 1957 and is classified among doctoral institutions with a high level of research activity. It has about 21,000 students, including 17,000 undergraduates. Nearly three quarters of its undergraduates are from Michigan. About 57 percent of students who start at the school and attend full time graduate with a bachelor’s degree within six years, according to federal data, a rate Western Michigan hopes to increase.

Thirty percent of Western Michigan students have enough financial need to qualify for federal Pell grants — a higher share than found at the state schools in Ann Arbor (18 percent) and East Lansing (22 percent).

Like state universities around the country, Western Michigan has been forced to adapt to lower levels of public funding than it once had. Montgomery said about 25 percent of its general operating funds come from the state government. The university obtains the rest of its annual funding through tuition, fees and other sources. “That’s why this additional support from philanthropy is really critical,” Montgomery said.

Western Michigan’s previous largest private donation was $100 million, announced in 2011. That helped establish its school of medicine.

Three institutions had shared the previous $500 million record for the largest private donation to a public university, according to the Chronicle list: Oregon Health & Science University, the University of California at San Francisco and the University of Oregon.