There's a kid at our mainstream public with an FM system and it isn't a big deal at all.

The upside of public is that they MUST accommodate your child's FM system, legally. Private schools might, but they are not legally obligated to do so, which means you have fewer avenues of recourse if the school is inconsistent in its application of her accommodations.

Thanks! Wasn't aware of the Montgomery County program. We were inclined towards private schools as we are looking for small class sizes. But it looks like DC area private schools don't really have small class sizes (10-15 kids).

I know you said private but have your looked at the Montgomery County program?

http://www.montgomeryschoolsmd.org/departments/special-education/programs-services/dhoh.aspx

We will be moving to the DC area this Fall and are looking for a private school for our daughter going into third grade. She has just been diagnosed with APD (left ear weakness only) and would need to use a personal FM system. Looking for an appropriate school with small class sizes that would accommodate a FM system. Any suggestions?