DES MOINES, Iowa — The board that oversees Iowa’s three public universities says its plan for a new two-year budget system will bring more predictability to tuition expenses for students and their families, but the unpredictability of available state funding could complicate that effort.

The Iowa Board of Regents, which provides support to the University of Iowa, Iowa State University and the University of Northern Iowa, announced recently a plan to fund the budget years that end in 2018 and 2019 with a combination of tuition increases and more state dollars. The board has typically planned one year ahead.

“By going to this new model, students and parents will know tuition rates well in advance, and the state will know our thinking on funding for two years,” said regents President Bruce Rastetter in a statement.

The nine-member board faces some challenges in delivering on its vision, in part because it’s become increasingly difficult to figure out how much money the Iowa Legislature will allocate each year to higher education. Student leaders at the three universities have publicly expressed frustrations about the growing cost of education, including an across-the-board tuition hike approved in July that came just weeks before the start of the new academic year.

University of Iowa student body president Rachel Zuckerman said the board’s announcement reflects an effort to listen to students’ concerns, but “now the Legislature and the governor have to play their roles.”

“This is all dependent on state appropriations and we don’t know how state appropriations will shake out,” she said.

In the last legislative session, the regents requested roughly $20 million in additional money for the schools. Gov. Terry Branstad recommended $8 million, and lawmakers eventually approved $6.3 million. They also allocated about $3 million in additional spending for Iowa’s community colleges, which are not part of the regents system.

The board sought about $21 million in new money for the universities in the 2015 legislative session and received about $6.3 million. The University of Iowa received no additional funding after a line item veto from Branstad.

Sen. Brian Schoenjahn, D-Arlington, who has worked on higher education funding, said the regents’ proposal would “require a long-term, bipartisan commitment by the Legislature.”

After lawmakers approved far less funding than the regents requested, the board approved tuition increases in July that generated about $19 million. The regents also voted to raise tuition last December. Cole Staudt, student body president at Iowa State University, said last-minute tuition increases are too difficult for students.

“It’s just a struggle to watch students come to me and say, ‘Hey, I really can’t afford this. I don’t know what I’m going to do,'” he said.

The specifics of the two-year model — 2 percent increases to tuition rates each year for in-state undergraduate students and 2 percent increases each year in state funding — is subject to change in the second year, said regents spokesman Josh Lehman.

“The plan is dynamic. What happens this year can affect it going forward,” he said.

In the end, the board is not formally asking the Legislature to approve two years’ worth of funding. At a Sept. 8 meeting, it plans to vote on its funding request for the first budget year — more than $656 million that includes $12.7 million in new money for the universities.

That request would double what the regents received last session. Branstad’s spokesman Ben Hammes declined to elaborate on whether the two-year plan is realistic, though he added in an email that “all budget requests are subject to the limitations of state revenue and Gov. Branstad will thoughtfully consider the request.”

The board has not released plans for tuition increases for out-of-state students, graduate students and professional students. That’s concerning to Joshua Schoenfeld, president of the graduate and professional student government at Iowa. He said the board has consistently raised tuition for these groups, and noted they were left out of recent tuition freezes.

“Once again, even when they’re talking about predictability of tuition, they’re really only talking about predictability of tuition for resident undergrad students,” he said.