The Montgomery County school board has agreed to look into shifting high school starting times to 8:15 a.m., a week after the county superintendent proposed delaying the first bell nearly an hour so that teenagers can get more sleep.

Superintendent Joshua P. Starr proposed the plan last week, citing a 56-page report by a study group he created and the health and safety benefits of getting enough rest.

Starr’s proposal was unanimously approved for further consideration and analysis by the Board of Education on Tuesday, an action that will begin a lengthy discussion of the issue, with community meetings, surveys and focus groups planned in coming months.

Under the proposal, high school opening bells, now at 7:25 a.m., would ring 50 minutes later. To support the change, middle schools would start at 7:45 a.m. — 10 minutes earlier than they do now — and the elementary school day would last an extra 30 minutes.

The proposed schedule changes are designed with the school district’s staggered transportation system in mind. Montgomery, like many other districts, has buses running multiple shifts to ferry high school, middle school and elementary students at different times of the morning and afternoon.

Parents turned out at Tuesday’s board meeting to support later start times, and board members weighed in on Starr’s proposal, asking questions about the study group, expressing concerns about expenses associated with such a move and inquiring about the possible timetable for any changes.

Board President Christopher S. Barclay (Silver Spring) asked about the link between student achievement and later high school schedules. The study group determined that research was inconclusive, with some experts finding benefits and some finding no improvement.

Starr said the proposal was not intended to affect grades or scores, but instead is intended to promote student health and well-being. “This is in no way, shape or form a panacea regarding student achievement or an achievement-gap reduction initiative,” Starr said.

Patricia O’Neill (Bethesda-Chevy Chase), the longest-serving member of the board, said she had been through debates on the issue in the past and appreciated the current proposal. “I do believe this is a most simplified version of what we could do,” O’Neill said.

Still, she said, “we need to look before we leap” and consider the full costs and possible unintended consequences.

Early estimates put the proposal’s price tag at $12 million a year, largely because more bus routes and vehicles would be needed. A more detailed cost analysis is planned.

“If there is a cost to this, which I do anticipate, we are going to have to figure something out in terms of potentially what we scale back to be able to do this,” or perhaps ask for more funding from the county, Barclay said.

At the same time, many voiced support for the concept.

“I have a lot of friends who are seniors who don’t take first periods or even second periods because they need to get more sleep, and I think this might help to address some of this issue,” said student board member Justin Kim, a senior at Poolesville High School.

Ann Gallagher, a parent who works for the Lloyd Society, a nonprofit group that advocates for at-risk youth, urged Montgomery to recognize school start times as a significant health concern.

“Montgomery County has the opportunity to lead the country in correcting this misguided approach to the health and safety of young people,” she said.

A final plan is expected to come before the board in the spring, with any changes taking effect in fall 2015, at the earliest.