I don't know about NE but I would be surprised if the school funding is a lot different than MT. In MT, the districts keep track of ANB (average number belonging). Payments for each student is made to the district claiming them. If a student transfers from one district to another, that funding can follow them. Sometimes, if a student is out of state or even country, they count as part of the district's ANB and funding flows from the state without affecting funds in their home state or country. I know of one small school that actively encourages parents to take in exchange students from all over the world in an effort to boost their ANB. In the case of nearby districts in state, the district must give permission for transfers or the ANB funding won't follow. 
If a district has excess capacity in seating or teaching staff, the transfer in, can help fund the district and even end up being a net plus.