NEW ORLEANS — The Archdiocese of New Orleans released a plan this week that will require changes in the structure of grades at 40 of the 85 schools under its auspices.

Under the goal of a “common good for all” and “creating uniformity,” the strategic plan calls for all elementary schools to consist of pre-K through grade 7, and all high schools to consist of grades 8 through 12.

Barring “extenuating circumstances,” the schools are being mandated to have their new structures in place for the 2015-2016 school year.

For some schools, such as Brother Martin High School, the change will be relatively minor.

Three years ago, the all-boys’ Catholic school in Gentilly added a seventh grade. Now it will have to remove the seventh grade to comply with the archdiocese’s plan.

For others, the changes will have a more drastic impact, such as Holy Cross, which has grades five through 12, and Christian Brothers, which has grades five through seven.

John Devlin, president at Brother Martin, said that the school fully intends to comply with the plan. “We’ve always been a team player in the archdiocese and will continue to be,” Devlin said.

While he said a possible decrease in enrollment is something the school will need to address, he is confident the numbers will even out.

Devlin said the school, which has 1,200 students, added the seventh grade in response to requests from parents, and that it has been a very successful addition.

“Our hope is that it will benefit not just all schools but all families who want their children to benefit from a Catholic education,” Devlin said, of the long-term goals of the restructuring.

Archdiocese spokeswoman Sarah McDonald said the archdiocese does have the authority to make such decisions over all four types of schools: direct-run, parish schools, sponsored school and religious order schools.

The schools will be required to submit a preliminary plan in the fall and a final plan next spring.

Schools can submit waiver requests, but McDonald said the deviations that the archdiocese will consider will be “extremely limited.”

McDonald said the restructuring will allow all students to transition from elementary to high school at the same time. She said it also will also help the financial viability of the schools in the long term.

The 34-page strategic plan also includes sections on Catholic identity, academics, governance, facilities management and marketing and development.

Also outlined is a goal of maximizing the benefits of the scholarship program, which on Tuesday was ruled unconstitutional by the Louisiana Supreme Court.

McDonald said that none of the plan is contingent on the controversial state-funded voucher program.

However, if the funding source goes away, McDonald said, the schools that lose students as a result will be assessed for viability and required to meet certain criteria, just as they are now.

One school, Cathedral Academy, will close at the end of this year, bringing the archdiocese’s total to 84. McDonald said 12 other schools are being closely reviewed for viability.

Jan Lancaster, superintendent of Catholic schools for the Archdiocese of New Orleans, said that she is optimistic that the state Legislature will find another way to pay for the voucher program.

“We’ve proven that it works,’’ she said, noting that voucher students at archdiocese schools showed a 20 percent increase in math scores on the LEAP test in 2012 compared with 2011 and a 10 percent bump in language arts scores.

The program has been in New Orleans since 2008. About 2,500 of the 38,000 students in archdiocese schools receive vouchers, and of that number 1,500 were under the pilot program and another 1,000 were added with the program’s expansion.

The Archdiocese of New Orleans has the highest number of voucher students in Louisiana.

Lancaster said that the program saves the state money. The average per-pupil cost for a student receiving a voucher is $4,000 a year, compared with $8,500 under the MFP.

“We’re saving the state literally millions,’’ she said.

“We’ve been doing an awesome job of educating children. When parents can choose, they choose Catholic education,’’ she said.