The majority of the District’s charter schools and all of the city’s traditional public schools plan to participate in a single, unified lottery to determine enrollment for next fall, a shift education officials hope will streamline what has often been a frustrating and chaotic process for families.

The new lottery also aims to give more certainty for school administrators, stabilizing rosters earlier in the year and minimizing an annual waiting-list shuffle that has had students switching schools throughout the summer and into the school year.

“The more people who get seats early in the process — because then they can plan and are not going out of their minds — and who get seats at schools they’re excited to go to, the better for everyone,” said Deputy Mayor for Education Abigail Smith, whose office is coordinating the lottery.

Until now, some families won admission to multiple schools while others were shut out entirely. The unified lottery uses a computer algorithm to maximize the number of students who get into at least one school they want to attend.

It’s a simple concept that’s beginning to take hold in such cities as Washington, where the rise of charter schools has created more choice and more uncertainty for parents. But it’s a complicated problem to solve, particularly when there aren’t enough seats in sought-after schools to go around.

Alvin Roth, an economist, shared the 2012 Nobel Prize for solving just this kind of problem. He designed the programs that match thousands of medical residents with hospitals, kidney donors with recipients and New York City students with high schools.

Roth is now a professor at Stanford University and chairman of the board of the Institute for Innovation in Public School Choice, which used his ideas to build algorithms for school lotteries in New Orleans and Denver and is creating the District’s system.

The institute aims to build “strategy-proof” school lotteries that are fair, efficient and transparent and can’t be gamed by even the most determined parent. The Michael and Susan Dell Foundation is funding the work for the District’s lottery. “Each city is unique,” said Neil Dorosin, the organization’s executive director. “The problems they face in enrollment and choice are not unique.”

In the past, each of the District’s charter schools had its own application process and ran its own lottery to determine enrollment when demand exceeded slots. The traditional school system conducted a separate lottery for admission to preschool programs, selective high schools and out-of-boundary schools.

Some students were admitted to more than one school, while others languished on waiting lists that continued shifting even after the first day of class each August.

Under that system, parents could apply to dozens of schools, then wait to see where their children were accepted before deciding where to enroll. Now, parents can apply only to a maximum of a dozen schools and need to decide earlier, before the lottery, where they really want their kids to go.

The unified lottery represents a new level of collaboration among traditional and charter schools, which compete for students and resources. The effort is voluntary, but the vast majority of schools — accounting for 95 percent of all seats for preschool through 12th grade — are participating. The 14 charter schools that don’t will continue to require separate applications.

Families can find details about the new lottery at, a centralized clearinghouse for information about school enrollment. Starting Dec. 16, parents will be able to fill out an application on the Web site that lets them rank their preference among up to 12 schools.

After the application deadline — Feb. 3 for high schools and March 3 for elementary and middle schools — the algorithm will click into action.

It will match each child with his or her highest-ranked school possible based on how the child’s lottery number and extra preferences, such as those offered to siblings of current students, stack up against others seeking a seat at that school.

“The best way for a family to interact with this is to list the schools they want in the order they really prefer them,” Dorosin wrote in an e-mail.

Dorosin said the program works to match students with their highest-ranked choices to the extent possible, meaning that ranking schools in their true order is the best way for parents to ensure a more desirable school. Parents should not put schools at the top of their list because they think their children have a better chance of getting into them; officials said that if parents reach for a popular school and their children don’t get in, that doesn’t hurt the chances of getting into schools lower on their list.

Lottery results will appear online March 31. Students will be waitlisted only at schools they ranked higher than the school to which they are offered admission. That’s another reason families should rank preferences honestly, Smith said.

“There is no benefit to putting choices in anything other than the order of where you most want to go,” she said, adding that outreach and communication efforts to parents will ramp up in coming weeks.

Kara Cruoglio and Mike Zakriski, parents of a rising preschooler, said the lottery change has kicked their school-research efforts into overdrive.

“I was prepared for the old way, so it’s a little bit jarring, two months before go time, for everything to change,” Cruoglio said. “But I’m optimistic that it’s going to help more people get spots.”

They were among a steady stream of parents who on Saturday morning filled Dunbar High School’s atrium, where representatives of traditional and charter schools set up booths to advertise their offerings during a fair organized by the Ward 5 Council on Education.

“Our original plan was to apply to literally everywhere and then make a decision later,” Cruoglio said, adding that she feels “like we have to get as much information as we can upfront.”

Families who miss the first round of the lottery or don’t get any seats can enter a second round in May, which will follow the same basic rules.

Smith led the development of the new process along with representatives from the traditional school system, the D.C. Public Charter School Board and three charter schools, Achievement Prep, Friendship and KIPP DC.

The budget for the project is about $1.4 million for the first year, most of which comes from private funders such as the New Schools Venture Fund. Officials said they expect the cost to drop significantly after the first year. They are considering whether and how to move long-term management of the lottery out of the deputy mayor’s office and into another agency or nongovernmental organization.