WASHINGTON — The Fairfax County school board is expected on Thursday to decide whether it should add the phrase “gender identity” to its school policy.

The change is aimed at protecting transgender students.

Supporters say it’s time to change school policy.

But some parents fear the change would allow genders to mix in bathrooms and locker rooms.

Some state lawmakers have expressed opposition to the proposal, calling it overreach by a local governing body.

Thirteen states and D.C. have laws protecting transgender students from discrimination.