Yu Ying also has small class sizes, 18 for prek+ (at least 2 teachers and a SN teacher if there is someone with an IEP), and class size shrinks in the upper grades. 15-17 kids per classroom in 3rd grade this yr. They have assigned seating at lunch for instance. They do inclusion very well but it is Chinese immersion language school so YMMV.

Contact the school's special ed coordinator directly. They should be willing to talk with you. If they're not, that's a big sign. My 4yo son with ASD is having a great experience at Inspired Teaching. We also liked CMI a lot and have heard good things about a few DCPS schools. I strongly recommend getting an Early Stages eval so that they can make recommendations for placement.

Look at the DC Special Ed Coop website. The charters which are members join this to get training and best practices. If a charter school isn't on this list you should probably look elsewhere.

They also have some resources for how parents of SN should evaluate schools / questions to ask.

CMI and Bridges will have the smallest classes. Most all others will be mainstream class with more or less push ins as needed / warranted in an IEP.

Have you looked at DCPS? Is it worth talking to early stages to see where they might place you (assuming they think you need more than your IB can offer).

Ah the annual lottery questions. Looking for a place that does special ed reasonably well, focus on in classroom support (ideally it'd be good for a few years). Teeing up our open house schedule... At Bridges now, not unhappy, but not convinced that it'd be a good solution K and up (seems class sizes get larger and push in support is more sporadic/not quite as supported). Mostly needing support for social language and attention. Didn't get to do good research last year s we weren't as aware of the needs when the lottery came around. I like the idea of CMI give their continued cap on class size and what I've heard. Who else is doing this support - the less academic stuff but stuff that is foundational - well, ideally with smaller classes? And what's the best way to judge that, other than reputation? How do you tease that out - at an open house, via questions, a call with someone in special ed? Given we'll almost certainly transition again in a few years (likely out of DC), I don't want to be school hopping within that.