In an acknowledgment that its evening high school program is an abysmal failure, the city is dismantling it and calling on school principals to design their own classes to target at-risk high school students.

Currently, about 28,000 high school students are referred to night classes and just 14,000 attend, with only half of those passing courses.

“The old program failed too many kids and it was time for us to make a change — the program was a dinosaur,” a spokeswoman for the city’s Department of Education, Kelly Devers, said. “This is a better and more viable way for students to get the credit they need.”

The night school classes are intended for high school juniors or seniors who are at risk of not graduating on time. Many principals and administrators considered the current system, which has been in place for years, to be a failure and waste of resources.

The city spends about $4.6 million on 12 night school programs across the city. Under the plan, money would be funneled directly into the schools, which are expected to offer classes directly before or after the school day instead of at night.

Principals can design and offer courses that its students need and pay their own teachers to hold classes instead of sending students to night programs at other schools. About three full-time consultant positions are expected to be eliminated in the restructuring.

Letters went out this week to the city’s high school principals asking for proposals on how they would address the needs of students who were previously sent to night classes.The schools will be able to offer classes before or after school or on the weekends. They are also able to cluster with other nearby schools to pool resources and are encouraged to combine these classes with the additional 37.5-minute classes added to the school day for struggling students under the recent teacher contract.

The executive director of the nonprofit group Advocates for Children, Elisa Hyman, said she was happy the city was tackling its night school program, but raised concerns about the proposal. She said that aside from tracking credit accumulation, there didn’t appear to be enough oversight to measure the effectiveness of the classes. The United Federation of Teachers also met last night with the city to discuss the new program. “We have concerns about academic standards being maintained at the affected schools, and whether all students in need will be adequately served under this new arrangement,” the president of the union, Randi Weingarten, said.