Pennsylvania’s state university system and its faculty union have agreed on a voluntary retirement program that could help the cash-strapped system as it faces its ninth straight year of projected enrollment decline.

Nearly one-fifth of the union’s 5,150 full-time faculty members would be eligible under the plan, which allows faculty to retire in phases over a three-year period. Their workload and pay would be gradually reduced, while they maintain full benefits. Those who qualify generally must be at least 60 and have worked at least 15 years in the system.

“It’s a great opportunity for our faculty,” said Kenneth M. Mash, president of the statewide faculty union, the Association of Pennsylvania State College and University Faculties. “I’m happy we were able to get it done, and we were able to work together relatively quickly to get it done.”

Just how much money the universities could save is uncertain. System officials have not released savings projections.

Mash estimated that a total of a couple hundred faculty members may opt in over the next few years. In a routine year, a couple hundred faculty members retire, he said. Under the phaseout plan, an additional 60 or 70 per year may choose to leave, he speculated.

“That’s a total guess,” he said. “I do know there are a lot of people who have asked me about it, who are excited about it.”

Interested faculty must notify the system of their interest by June 12; the phaseout would begin in the fall. Faculty members typically teach eight classes per year.

The idea is not new. Pennsylvania State University, which is not part of the state system, has offered phased-out retirements, as have other schools.

At the state system, the plan comes as another 2 percent enrollment decline is projected for the fall and some universities are struggling to close projected budget gaps. The 14-university system dipped below 100,000 students last school year for the first time since 2001. The universities are: Bloomsburg, California, Cheyney, Clarion, East Stroudsburg, Edinboro, Indiana, Kutztown, Lock Haven, Mansfield, Millersville, Slippery Rock, Shippensburg, and West Chester.

Daniel Greenstein, system chancellor, was not available for comment, a system spokesperson said.

In announcing the agreement last week, Cynthia Shapira, chairwoman of the board of governors, said the program “is an example of system leadership and faculty working together.”

Mash said he understands that the college system’s administrators see the plan as an opportunity to save money by replacing senior professors with cheaper faculty or not replacing them at all, depending on their subject and if it has been hit by a decline in enrollment.

“We’re concerned about that,” he said, noting that the union will monitor the plan’s implementation.

The system is likely to face another cash crunch for 2019-20. But just how much cutting will be necessary won’t be known until the legislature passes its budget. Administrators asked for a $38 million funding increase, and Gov. Tom Wolf proposed $7 million.

They also have begun negotiations on a new contract with the faculty union; the current pact expires June 30. Faculty agreed to a one-year contract last time, following a three-day strike in 2016.