SIL and SDA OT Assessments — What Support Coordinators Need to Know

Reading time: 12 minutes  |  Audience: Support Coordinators & Allied Health Professionals  |  Updated: April 2026

For support coordinators, Supported Independent Living (SIL) and Specialist Disability Accommodation (SDA) applications sit among the most complex and consequential work in the role. Get the clinical evidence right and a participant gains appropriate housing and the support they need to live independently. Get it wrong — or submit an application without a thorough occupational therapy assessment — and the NDIA will almost certainly reject it.

Yet the occupational therapist’s role in SIL and SDA applications remains widely misunderstood, even among experienced support coordinators. Many coordinators treat the OT report as an administrative formality rather than the clinical cornerstone it actually is. This guide sets out exactly what OT assessments for SIL and SDA involve, what distinguishes a strong report from a weak one, when to refer, and how to work effectively with an OT to give your participant the best possible outcome.

SIL and SDA — A Brief Overview

Before examining the OT’s role, it is worth clarifying the distinction between SIL and SDA, as the two are often conflated — including in applications to the NDIA.

Supported Independent Living (SIL)

SIL is a support funding category, not a housing type. It funds the assistance and supervision a participant needs to live as independently as possible in shared or individual accommodation — covering tasks such as personal care, cooking, cleaning, medication management, and community participation. SIL funding is included in a participant’s plan under Core Supports and is typically the most expensive ongoing support in a plan.

Specialist Disability Accommodation (SDA)

SDA is a housing funding category for participants who have an extreme functional impairment or very high support needs and require a home with specific accessibility or design features. SDA funding pays for the physical dwelling — it does not pay for support workers. SDA-eligible participants typically also receive SIL, but the two are assessed and funded separately.

Why the OT Assessment Is the Most Critical Piece of Evidence

The NDIA does not take SIL or SDA applications at face value. Both require detailed clinical evidence demonstrating that the level of support requested — or the housing design features required — is genuinely necessary given the participant’s disability-related functional impairment.

A support coordinator’s case notes, a carer’s statutory declaration, or a GP letter alone will not satisfy this evidentiary requirement. What the NDIA needs — and what consistently determines whether SIL and SDA applications succeed or fail — is a comprehensive functional assessment from a qualified occupational therapist.

The OT assessment provides three things the NDIA cannot get from any other source:

1. An objective, standardised measure of the participant’s functional capacity across all relevant daily living domains — not the participant’s or carer’s subjective account
2. A clinically justified link between the observed functional impairment and the specific level or type of support being requested
3. A professional attestation from an AHPRA-registered clinician who has directly observed the participant in their actual environment

Without these three elements, the application is built on advocacy rather than evidence — and the NDIA will treat it accordingly.

What an OT Assesses for SIL

A SIL-focused OT assessment is a comprehensive functional capacity evaluation that specifically quantifies the participant’s support needs across all activities of daily living. The goal is not only to establish that the participant needs support, but to document precisely how much support, for which tasks, and at what time of day.

Daily living domains assessed

What the SIL OT report must quantify

A SIL OT report that simply states “the participant requires 24-hour support” will not be sufficient. The NDIA expects the report to:

• Specify the nature of support required for each task — supervision only, verbal prompting, physical assistance, or full hands-on care
• Estimate time per task and frequency per day or week — so the NDIA can validate the proposed roster of care
• Justify any high staff-to-participant ratios (such as 2:1 support) on clinical grounds
• Differentiate between supports that are disability-related and those that would be required by anyone (such as basic cooking) — the latter are not fundable under SIL
• Explain why informal support alone is insufficient to meet the participant’s needs safely and sustainably

What an OT Assesses for SDA

SDA eligibility is more narrowly defined than SIL. The NDIA funds SDA only for participants who have an extreme functional impairment or very high support needs — and whose housing needs cannot be met by standard or modified housing. The OT assessment for SDA must establish both of these things.

Establishing extreme functional impairment

The OT must document functional impairment that is severe enough to meet the NDIA’s SDA eligibility criteria. This typically involves:

• Standardised assessment scores demonstrating severe limitations in multiple daily living domains
• Documented need for a high-physical-support environment — such as ceiling hoist infrastructure, step-free access throughout, or a highly accessible bathroom designed for full-assistance showering
• Evidence that standard housing — even with assistive technology and minor modifications — cannot adequately meet the participant’s functional needs

SDA design categories and the OT’s role

SDA dwellings are classified into four design categories, and the OT’s assessment determines which category the participant is eligible for:

The OT report must clearly articulate which design category is required and why — not simply assert that the participant “needs SDA.” The NDIA expects the clinical reasoning to map specific functional impairments to specific design features.

SIL vs SDA Assessments — Key Differences

What Makes a Strong SIL or SDA OT Report

Not all OT reports are equal — and the difference between a strong SIL or SDA report and a weak one is frequently the difference between approval and rejection. Here is what distinguishes the best reports:

Standardised assessment tools are used and cited

Strong reports reference validated, standardised assessment instruments — such as the WHODAS 2.0, Functional Independence Measure (FIM), Barthel Index, or condition-specific measures — and present the scores alongside narrative interpretation. A report based solely on interview and observation, without standardised measures, lacks the objective grounding the NDIA expects for high-cost decisions like SIL and SDA.

Support needs are task-specific and time-quantified

For SIL, vague statements like “requires 24-hour care” are insufficient. The NDIA expects to see exactly what support is needed, for which tasks, for how long, and at what frequency — across a representative 28-day period. An OT who can produce a well-evidenced 28-day schedule directly aligned with their functional findings gives the support coordinator the strongest possible foundation for the SIL submission.

The clinical rationale is explicit, not implied

Every recommended support level or design feature must be linked to a specific observed impairment. The report should never expect the reader to make clinical inferences. If a participant requires 2:1 support for showering, the report must explain why — not simply state it.

The environment has been directly observed

For SDA in particular, the OT must have visited the participant’s current housing to document why it is inadequate. An SDA report based only on an interview without a home visit is far more likely to be questioned by the NDIA.

Future needs are considered

For participants with progressive conditions, a strong report addresses not only current needs but the trajectory of those needs — and recommends SDA design features or SIL structures that will remain appropriate as the condition advances.

Why SIL and SDA Applications Get Rejected

Understanding the most common failure points allows support coordinators to prevent them before submission, rather than managing a rejected application after the fact.

When to Refer Your Participant for a SIL or SDA OT Assessment

Timing is critical. Referring too late creates pressure to rush a report that should be thorough, while waiting for “more evidence” can leave a participant in unsuitable housing for months longer than necessary.

Refer for a SIL OT assessment when:

• A participant is transitioning from the family home to independent or supported living for the first time
• A participant’s current SIL hours are due for review and you believe they are insufficient or excessive
• A participant’s condition has deteriorated significantly since their last assessment
• A participant’s informal support network has changed — such as an ageing parent who can no longer provide care
• A participant has been discharged from hospital or rehabilitation and needs supported housing for the first time
• A participant in an existing SIL arrangement wants to move to a different setting with different support requirements

Refer for a SDA OT assessment when:

• A participant’s current housing cannot be adequately modified to meet their access needs, even with home modifications
• A participant is on a SDA waitlist and needs an updated assessment to confirm eligibility
• A participant’s physical impairment has progressed to the point where standard housing is no longer appropriate
• A participant requires High Physical Support design features — such as ceiling hoist infrastructure — that cannot be retro-fitted to standard housing
• A participant is leaving the family home and the family home cannot be modified to meet their needs

How to Work Effectively with an OT as a Support Coordinator

The relationship between an OT and a support coordinator on a complex SIL or SDA application should be genuinely collaborative — not transactional. Here is how to make that collaboration work well:

Brief the OT thoroughly at referral

Don’t simply make a referral and wait. At the point of referral, share everything the OT needs: the participant’s current plan goals, existing reports, family situation, current support arrangements, any behaviour support plan, and what you are specifically trying to achieve with the application. A well-briefed OT produces a more targeted and useful report.

Arrange for carer or family input during the assessment

For participants who have difficulty self-reporting — which includes many SIL applicants — the OT needs direct input from the person who knows them best. Make sure a carer, family member, or existing support worker is available during the assessment. Their observations of typical daily functioning are often more clinically useful than the participant’s own account.

Share the proposed roster of care before the report is finalised

If you are developing a 28-day roster of care alongside the OT assessment, share your draft with the OT before they write the final report. Identify any discrepancies between the proposed support hours and the clinical findings — and resolve them before submission, not after a NDIA request for further information.

Review the draft report critically

As a support coordinator, you know what the NDIA looks for in a SIL or SDA submission. Review the draft OT report with that knowledge. If you see gaps — missing standardised assessment scores, unsupported claims, vague support descriptions, or a failure to address the informal support question — raise them with the OT before the report is finalised.

Keep communication documented

For complex applications that may eventually be reviewed or appealed, maintain a clear record of communications between yourself, the OT, the participant, and the NDIA. If a report is ever challenged, contemporaneous documentation of the assessment process is valuable.

Process and Realistic Timelines

Frequently Asked Questions

Summary

SIL and SDA OT assessments are among the highest-stakes clinical reports in the NDIS system — and the quality of those reports directly determines whether participants receive the housing and support they genuinely need. As a support coordinator, your role is to refer early, brief the OT thoroughly, review the draft report critically, and ensure the roster of care and OT findings are consistent before submission.

At TEAH, our occupational therapists bring specialist experience in SIL and SDA assessments — producing detailed, standardised, NDIA-quality reports that give your participant’s application the strongest possible foundation. We work across Darwin (NT), Perth (WA), Brisbane (QLD), and Victoria, with a dedicated intake team that understands what support coordinators need.