PORTLAND, Ore. — Oregon school districts must decide by March 1 whether to accept students from other districts under a new open enrollment law approved by the Legislature this year.

The change raises a number of complicated questions for school districts. They can boost their enrollment — and state funding — by taking students from other districts. But schools have no control over which students they accept and might have to admit students they're not equipped to teach, such as those with limited English or special needs.

Oregon already allows students to transfer to a school outside their neighborhood district if both districts agree. In June, the Legislature decided that only the receiving district should have to give its blessing.

"It's an important change, but it just makes it easier for folks to get their kids into different districts if that's what they choose to do," said Christine Miles, spokeswoman for the Oregon Department of Education.

Transfers under the new law start next school year, although the measure technically takes effect on Sunday.

Budget struggles have kept state support for schools largely stagnant despite growing enrollment and costs. That has forced school boards to close schools, lay off teachers and increase class sizes.

Proponents argue that competition among schools would force them to improve. Others worry about the effects it will have on districts that lose students. The law doesn't provide money to help a district if it faces a quick exodus of pupils, although existing school funding formulas could provide relief for some districts in such a situation.

As school boards mull their decision, state education officials published a memo in October to help them understand the new law.

The school board for Portland Public Schools, the state's largest district with 47,000 students, hasn't yet taken a formal look at a future open enrollment policy, said Robb Cowie, a district spokesman. District officials are focused first on an upcoming period for parents to apply for transfers to schools outside their neighborhood but still in the district.

"We do expect that the board will be looking at the issue and determining whether or not Portland Public Schools will open itself to enrollment from other districts," Cowie said.

Portland last year accepted a total of 815 additional students through mutual agreements with other districts under Oregon's existing open enrollment law.

Districts must announce by March 1 how many students they will accept from other districts, if any. They can cap the enrollment in certain grades or schools, or they can limit transfers to a certain geographic region, the state advised.

Districts cannot discriminate or give a preference based on race, religion, gender, sexual orientation, English proficiency, disability, income or athletic ability. After the deadline, districts can't change the number of transfer students they'll admit.

Parents must apply for a transfer by April 1, and the district must notify the students they select by May 1. Districts that receive more applications than available positions are required to select which students are accepted without discriminating, and the state suggests using a random lottery.