Massachusetts Governor Charlie Baker and Boston Mayor Marty Walsh have partnered to launch a program that makes public college tuition-free for low-income Boston residents. Boston joins Tennessee, New York and Rhode Island in pushing for free college, but affordability advocates wonder how many students will benefit from the plan.

The Republican governor and Democratic mayor say their "Boston Bridge" program will start with high school students graduating this spring.

To qualify, a student must be eligible for federal Pell grants and enroll full-time at Bunker Hill Community College, Roxbury Community College or Mass Bay Community College. He or she must also complete a two-year associates’ degree on time before transferring to one of the state’s four-year public colleges, where they must maintain a 3.0 grade point average and graduate within two years.

“College affordability too often serves as a barrier for students in the Commonwealth seeking to complete a degree, and this program is intended to provide more opportunities for a quality education,” Baker said in a statement.

College affordability advocates, though, say the program is too limited in scope.

"The way I describe it is, 'Free with more footnotes than a journal article,'” said Barmak Nassirian, director of federal relations and policy analysis for the American Association of State Colleges and Universities. “There are numerous conditions and qualifications.”

“The system has gotten too complicated for most people's comprehension, and the only thing people have to show for it is this boat anchor of debt tied around their necks," Nassirian added, questioning how many students would qualify for the program.

"The majority of students today are not actually 18 years old. They're working adults. They're veterans. They're people who are going back after some years out of college," Nassirian said. "Most can't take a full load the way a residential college student can."

Under the plan, state and city taxpayers will cover tuition and fees for qualifying students, who must pay their own room and board. 

City and state officials tell WGBH News that the program will cost between $14,000 to $15,000 per student, covering the third and fourth years of college once an eligible student transfers from community college to a state university. That bill will be split by city and state taxpayers, and total costs will ultimately depend on how many students enroll and graduate with a bachelor's degree.

Higher education analysts predict few students will persist.

Zac Bears, executive director of PHENOM, a coalition of students and families advocating for debt-free college in Massachusetts, says the Boston Bridge program doesn't address the root causes of high costs and student debt at public colleges.

"Boston Bridge is a small program with little or no new funding, and that means it can't address the $500 million dollars the state has cut from public colleges and universities since 2001,” Bears said, adding that Baker has proposed a budget that will lead to cuts as well as tuition and fee hikes at all 29 Massachusetts public colleges and universities.

Bears says he worries some Boston students will think they have a free pass.

Last spring, appearing on WGBH's Boston Public Radio, Walsh announced a separate plan to make two years of community college free for some Boston Public School graduates, but, it turns out, few students have been eligible for that program.

"Since launching our program in 2016, we have helped fifty Boston Public Schools graduates attend community college," Walsh said in a statement. "This partnership means that a free bachelor's degree is within reach for all of Boston's low-income high school students."

Earlier: Free Community College In Boston? Not Quite

Related: Could Rhode Island Make Free College A Reality?