You might look at the Summit School, which specializes in kids with average to above average cognitive ability but language based disorders. The founder is a PhD SPL and frequently gives talks on dyslexia.

You can move to change the IEP once you are in a school system. You might have to ask for new assessment data (or pay for it yourself). You really need good reading (and probably overall speech/language) testing. The reading testing should provide grade level achievement and be broken down by discrete skills like phonics, decoding, fluency, accuracy, etc. If the child is reading below grade level and they have normal intelligence (which you can document with cognitive testing), you should be eligible for an IEP.

Good reading programs for dyslexia are Wilson and Phonographix. MCPS offers Wilson beginning in 3rd grade (I saw this on the MCPS website). I think you need to have an IEP to get it, but I am not sure. It may be that you can get it thru EMT process (which is like pre- or less than IEP level school assistance).

Is the child covered by medical insurance? Either thru your family plan or thru the terms of guardianship? Medical insurance sometimes pays for some speech/language testing. It's worth checking.

In theory, schools shouldn't be offering remediation for dyslexia in middle school and high school because kids shouldn't be able to proceed that far without being identified. A school can't say, "you have dyslexia and you are reading below grade level, but sorry you're too old to give any reading tutoring."

OP, sometimes kids with learning needs that can't be met in public school get placed in private schools. My mind is blanking as to what this is called, maybe my fellow posters can help.

It's not common but it can happen. For example, the Chelsea School in Maryland is private takes public school kids who don't pay tuition, but it sounds like you are looking in Virginia. I'm sure they have the same thing there.

I know of parents who homeschool for 1-2 years and hire an academic language therapist to provide daily tutoring and perhaps teach 1-2 subjects while the parent teaches the other subject areas. The child is then ready for a mainstream public or private school, often with support from both the school and 2-3 hours a week from a tutor or therapist. It is an investment in time and money, but it seems to pay off.

Try the Barton program for dyslexia. It helped my child