What about eligibility concerns for children that are suspected of having ADHD that is negatively impacting them in their educational setting and performance yet do not have a formal diagnosis.... is this the parent's responsibility first and foremost before the school district is required to act by evaluating the student for potential IDEA eligibility?
Under 'Child Find' (for both IDEA and 504), the School District has the legal duty to locate, identify and serve students within their geographic boundary that is suspected of having a qualifying disability that impacts a major life function (504 standard) or a qualifying disability that is need of specialized instruction (IDEA standard). This triggers when the institution itself or its employees know, suspect or should have known that a particular child MIGHT meet the eligibility criteria. They don't have to know but just suspect that they COULD qualify.
This is the entire point and purpose of the general education safety net program we call Response to Intervention/Problem Solving Team. In many cases, it will be our general educators that suspect or see problems with students in their classes or administrators see. The parents are not considered experts under this law and may not realize or see that their child might have a "disabling condition" that negatively impacts them in their educational setting/performance. RTI/PST is the initial step that doesn't require parental consent or notice because it's available for all students but if the changes or additional assistance provided under RTI/PST is not successful over about 6 to 9 weeks then the Institution or employees should refer the student to the special education department for a Referral Meeting to potentially get parental consent and start the evaluation process.
The School would be responsible for testing and diagnosis and not the parent. This is the purpose of Autism or ADHD rating scales prior to moving to next steps of securing an actual diagnosis. It doesn't fall back on the parent IF THE SCHOOL DISTRICT WAS THE ONE THAT SUSPECTED, KNEW, OR SHOULD HAVE KNOWN.