BOSTON — A third of all UMass students will qualify for free tuition paid for by the new income surtax on the state’s highest earners under a plan the Healey administration rolled out Wednesday on an expansion of state financial aid.

The governor announced that $62 million in new program funding included in the fiscal year 2024 budget she signed this summer will go toward expanding the MASSGrant Plus program, which her administration says will benefit approximately 25,000 students attending the state’s community colleges, state universities and the University of Massachusetts.

The MASSGrant Plus expansion will cover the full cost of tuition and fees for Pell Grant-eligible students, including the federal government-determined expected family contribution, and an additional allowance of up to $1,200 for books and supplies. It does not cover housing costs.

Most Pell Grant recipients typically come from families with an annual income of $40,000 or less or have otherwise difficult financial situations. About a third of UMass students are eligible for Pell Grants, according to university President Marty Meehan, as are 40% of students at Salem State University, according to its president, John Keenan.

“MASSGrant Plus Expansion by the Healey-Driscoll administration is a game-changer for state university students. It is simply historic. I know at Salem State University, 40% of our students are Pell-eligible, and hundreds of our students are considered as being from middle-income families,” Keenan said in a statement. “This unprecedented investment will allow more of the Commonwealth’s students to pursue their dreams of a college education. It’s a win for them and a win for the future Massachusetts workforce,”

In addition to expanding financial aid for the lowest-income students, the expansion program also seeks to alleviate college costs for middle-income students.

Those from families that earn between $73,000 to $100,000 annually in adjusted gross income will have their costs for tuition and mandatory instructional fees reduced by up to half of out-of-pocket expenses, the Healey administration announced Wednesday.

Middle-income students must be enrolled full-time to qualify, while the grant funding will extend to full- and part-time Pell-eligible students. The financial aid only applies to undergraduate students, according to the administration.

The program is retroactive to the start of this fall semester. The money had been approved before most schools started, when Healey signed the annual budget in August, though the program details were only released Wednesday.

The $62 million program uses a pot of newly available revenues stemming from a tax increase on the state’s highest earners.

State budget writers had an extra $1 billion available this year for education and transportation investments, made available by a surtax voters approved last year on individuals’ annual income over $1 million — $84 million of which was earmarked for MASSGrant Plus.

The administration is estimating their plans to make college tuition-free for Pell Grant eligible and up to half-price for middle-income students will cost $62 million, but is leaving the extra $22 million for wiggle room and other financial aid initiatives.

A press release from the Healey administration says the remaining funds will also help implement a new law that allows qualifying undocumented immigrants who have completed high school in Massachusetts to access state financial aid.

Former Gov. Charlie Baker launched MASSGrant Plus in 2018 to cover unmet costs of tuition and mandatory fees for low-income community college students. It started with a $7.5 million investment, which at the time doubled the amount available previously for community college scholarships.

After years of significant investment in K-12 education, advocates have seen the passage of the income surtax as an opportunity to make education more affordable at both the beginning and advanced stages of a student’s career.

In addition to the MASSGrant Plus expansion, the Legislature this year passed another one of Healey’s priorities — a $20 million last-dollar free community college program for Bay Staters over 25 without a college degree, called MassReconnect.

With everyone in Massachusetts facing the state’s high costs of living, the governor has said that investments in higher education will help the state’s economy and encourage an educated workforce to put down roots in Massachusetts.

“For so many Massachusetts residents, higher education can be the ticket to their future career and economic stability. Our employers are looking for graduates of Massachusetts’ exceptional public colleges to meet their workforce needs, and those graduates are most likely to stay in Massachusetts. But far too many people are held back from pursuing the education of their choice because of high costs,” Healey said in a statement.

“This expansion of MASSGrant Plus will open doors for more students to access higher education, which will strengthen our economy as a whole. We’re grateful to our Legislative partners for making this funding available and look forward to our continued collaboration to make Massachusetts more affordable.”

Healey is announcing the program expansion during a visit to Salem State University Wednesday morning.