Enrollment in traditional public schools has been shrinking since charter schools began operating in 1997.
This year, there are about 131,000 students in district schools, and a record 67,000 in charters. Each student in a Renaissance charter costs the district $3,000 to $4,000 a year, depending on the school.
Superintendent William R. Hite Jr. said the district must continue overhauling its toughest schools.
Since its inception, the Renaissance program "has provided good neighborhood options to students and families in some of our lowest-performing neighborhood schools, working in partnership with high-performing charter operators," Hite said in a statement.
Deputy Superintendent Paul Kihn said the district has been cheered by the gains seen at schools given to charters, but wants to fine-tune the process this year.
"We were eager to do it in a way that better meets the needs of families," Kihn said.
Advisory councils at each school designated for overhaul had previously chosen among charter providers vying to get a contract. Now, the district will match one or two schools with providers, and then parents will vote on whether to go with that provider or stay in the district.
If parents vote against the charter option, they will not be given the option of a "Promise Academy," the in-district turnaround model. Kihn said the district was not adding any Promise Academies this year.
"That's not to say that it will be business as usual," Kihn said.
Once the schools to be turned around are chosen - on the basis of academic performance, school safety, and other factors - parents will have about a month to research the charter provider assigned to them. Only charter organizations with a track record of successful Philadelphia turnarounds will be considered, Kihn said.
Then parents will vote in mid-April on whether to become charters, with School Reform Commission approval scheduled for May 15.
The schools to be designated for conversion will be named in the next few weeks, Kihn said. They are likely to be elementary schools with at least 550 students.
A December 2013 report analyzing the district's current Renaissance schools emphasized that they have made gains. All have seen better attendance and school climate, as measured by suspension and serious incidents. Most of the schools have seen increases in state test scores, particularly during the first year of conversion.
Elementary school charter conversions have been more successful than changes to high schools.
Kihn said the district has taken those messages to heart.
"We're very, very interested in something we know is going to be successful," he said.