SSI Age 18 Medical Evidence: What Documentation You Need for the Redetermination

The evidence that proved your child's disability for childhood SSI won't be enough at 18. The standard changes completely, and the medical record needs to change with it.

Under the childhood standard, the question was whether the condition caused "marked and severe functional limitations." At 18, the adult standard asks whether the impairment prevents the individual from performing "any substantial gainful activity" in the national economy — any job, anywhere, for at least 12 consecutive months. Different question, different evidence.

The Shift in What DDS Is Looking For

Missouri's Disability Determination Services (DDS) evaluates the medical evidence using the adult Sequential Evaluation Process. After confirming the impairment is medically determinable and severe, the examiner assesses residual functional capacity — what the individual can still do despite their limitations.

This is where childhood evidence falls short. An IEP from 9th grade shows educational support needs. A DDS examiner reviewing an 18-year-old's case needs to understand work capacity. Can this person follow multi-step instructions in a workplace? Sustain attention for an 8-hour shift? Navigate coworker interactions? Maintain attendance reliably?

The records that answer those questions often don't exist yet unless you've been building them deliberately.

The Five Categories of Evidence to Gather

1. Clinical and Diagnostic Records

Pull every treating provider's records covering at least the last 24 months:

• Psychiatric evaluations documenting diagnosis, medication response, functional observations, and prognosis. Bare diagnostic statements ("Patient has autism spectrum disorder") aren't sufficient. The evaluation should describe how the condition manifests in daily functioning.
• Neuropsychological testing with standardized scores in cognitive ability, adaptive behavior, processing speed, and executive function. The Vineland Adaptive Behavior Scales, the ABAS-3, or similar instruments provide the quantifiable data DDS examiners rely on.
• Therapy notes from occupational therapy, speech therapy, behavioral therapy, or counseling. Session notes that document ongoing deficits carry more weight than a discharge summary from years ago.
• Medication records showing current prescriptions, dosage history, and any side effects that affect functioning.

2. Psychoeducational Evaluations

A comprehensive psychoeducational evaluation is often the single most powerful piece of evidence. It bridges the educational and clinical worlds — testing cognitive ability, academic achievement, adaptive behavior, and processing skills in a standardized format that DDS examiners are trained to interpret.

If your child's most recent psychoeducational evaluation is more than two years old, consider requesting an updated one. The school district may fund this through the IEP process if the student is still enrolled. After graduation or aging out, you'd pay for a private evaluation — typically $2,000 to $4,000 for a comprehensive battery.

The evaluation should explicitly address work-related capacities: ability to follow instructions, maintain pace, interact with supervisors and coworkers, and adapt to routine changes.

3. School Records

The school transition file provides critical evidence, especially:

• The most recent IEP showing goals, accommodations, modifications, and related services. The scope of support needed in school translates directly to the scope of support that would be needed in a workplace.
• Summary of Performance (SOP), required by IDEA when a student exits special education. It summarizes the student's academic achievement, functional performance, and recommendations for post-school supports.
• Functional Behavioral Assessments (FBAs) and Behavior Intervention Plans (BIPs) documenting behavioral challenges and the interventions required to manage them.
• Progress monitoring data showing the rate of skill acquisition. If goals that were set two years ago haven't been met, that data demonstrates persistent limitation.
• Transition assessment results — vocational interest inventories, job readiness evaluations, community-based assessment outcomes.

4. The Function Report

Form SSA-3373 (Function Report - Adult) is your narrative opportunity. The SSA sends this form to the claimant or their representative, and the answers directly shape the DDS examiner's understanding of daily limitations.

This is not the place for optimism. Describe the worst days, not the best ones.

Be specific: "Can make a peanut butter sandwich if all ingredients are placed on the counter, but cannot plan a meal, use the stove safely, or remember to turn off appliances" is useful. "Needs help with cooking" is not.

Cover every category: personal care, meal preparation, household chores, shopping, money management, social interactions, concentration and task completion, and ability to handle changes in routine. For each one, describe what the individual can do, what they can't do, and what support is currently provided.

5. Work Capacity Evidence

If the individual has participated in any work-related programming — Pre-Employment Transition Services through Missouri Vocational Rehabilitation, community-based work assessments through the school district, supported employment, or volunteer positions — get written documentation from the job coach or supervisor.

Specifically useful: staff-to-participant ratios during work tasks, the number and type of prompts needed per hour, productivity levels compared to competitive employment standards, and a professional assessment of whether the individual could maintain employment without ongoing job coaching.

If there's no work experience at all, get clinical documentation explaining why the individual hasn't been able to participate in work-related activities.

What Happens If Evidence Is Insufficient

If DDS determines the existing medical record can't establish whether the impairment prevents substantial gainful activity, they'll order a consultative examination (CE) at SSA's expense. The CE is conducted by a provider contracted with DDS — typically a brief evaluation by a doctor who has never met your child.

CEs aren't inherently bad, but a 20-minute appointment with a stranger can't capture the complexity of a developmental disability the way longitudinal treating-provider records can. The strongest approach: submit comprehensive evidence proactively so the DDS examiner has everything needed before considering a CE.

The Missouri SSI at 18 & Adult Disability Benefits Guide includes an evidence-gathering checklist organized by document type, with specific guidance on what DDS examiners look for in each category and how to request records from schools, providers, and state agencies.

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