<p>Legally, there is no distinction as such. IEP’s can be, and frequently are, about accommodations only without any modifications of the content. Schools can be deceptive about this because IEP puts further obligations on them that they would not like particularly.</p>
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<p>Dunno about 504s, but for IEP’s, they aren’t changed without the full IEP team approval, even if the teacher does a “few quick tests”</p>