My spouse is a special ed teacher so this is based on my experience only... but I think it is more a factor of the school having more time and resources availab

My spouse is a special ed teacher so this is based on my experience only... but I think it is more a factor of the school having more time and resources available. The school district my spouse worked at sadly has many more children from single parent and poor households and this essentially raises the bar on who they can qualify. My own city's school district does not have as many students like this, so milder cases still tend to qualify. There are certainly standards in place which should standardize this across school district lines, but balancing the maximum student slots available with the budget is more of a challenge for poor school districts. In Ohio at least I have a feeling some wealthier school districts are using IEPs to artificially raise school wide student test scores as well, since these students don't always count towards the scores and rankings (I am not sure exactly how it works as it depends on the grade level and other specifics).