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A WPI assessment is body-system specific
In NSW workers compensation, permanent impairment assessment is performed by trained medical assessors using the NSW guidelines. AMA5 is used in many body systems, but NSW modifications control where they differ. The practical issue is not just the final percentage; it is whether the accepted injury, medical records, method and threshold consequence have been checked properly.
Physical threshold
SIRA states physical injury permanent impairment compensation generally requires 11% or more permanent impairment.
Primary psychological threshold
SIRA states primary psychological injury generally requires 15% or more permanent impairment, and secondary psychological injury is treated differently.
One claim warning
SIRA notes a worker may only make one permanent impairment compensation claim per injury in most post-2012 cases, so timing and evidence quality matter.
How the permanent impairment assessment process works
Start with the accepted injury
The assessor should know exactly what injury or disease is being assessed. A lumbar spine injury, rotator cuff tear, hearing loss claim, psychological injury, burn scar or multiple-injury file can involve different medical methods and different records. If the referral asks the wrong question, the WPI report may be less useful even if the examination itself was careful.
Check maximum medical improvement
Permanent impairment assessment should usually wait until the injury has stabilised. If surgery, rehabilitation, injections, counselling, hearing assessment, scar management or specialist treatment is still likely to materially change the condition, the timing of the assessment may need to be reviewed.
Send the right material
A strong WPI file is not just an appointment. The assessor may need imaging, operation notes, specialist reports, GP records, certificates of capacity, audiology or lung function testing, treatment history, psychological reports, photos of scarring where relevant, and work-duty evidence that explains how the injury affects function.
Review deductions and combined impairments
The report should explain any deduction for a previous injury, degeneration or non-work condition. Where multiple impairments arise from the same injury or incident, the final WPI may need proper combination rather than treating each issue in isolation.
Why the percentage matters
The WPI percentage can affect Section 66 lump sum compensation, medical expense time limits, weekly-payment planning and whether work injury damages threshold advice is needed. It does not automatically decide every part of the claim, and it does not guarantee a settlement. The practical question is whether the percentage is based on the correct injury, correct guideline method and complete evidence before it is used in negotiation or dispute strategy.
Choose the assessment guide closest to the injury
Spine and nerve-root injuries
Back, spine and neck
How assessment works, evidence to prepare, common disputes and report checks for this injury type.
Upper limb injuries
Shoulder, arm and hand
How assessment works, evidence to prepare, common disputes and report checks for this injury type.
Lower limb injuries
Hip, knee, leg, ankle and foot
How assessment works, evidence to prepare, common disputes and report checks for this injury type.
Head and neurological injuries
Head, brain and neurological
How assessment works, evidence to prepare, common disputes and report checks for this injury type.
Psychological injury
Psychological injury
How assessment works, evidence to prepare, common disputes and report checks for this injury type.
Hearing injuries
Hearing loss and tinnitus
How assessment works, evidence to prepare, common disputes and report checks for this injury type.
Respiratory and exposure injuries
Respiratory and dust disease
How assessment works, evidence to prepare, common disputes and report checks for this injury type.
Skin, burns and scarring
Skin, scarring and burns
How assessment works, evidence to prepare, common disputes and report checks for this injury type.
Chronic pain and CRPS
Chronic pain and CRPS
How assessment works, evidence to prepare, common disputes and report checks for this injury type.
Serious and traumatic injuries
Amputation and serious injury
How assessment works, evidence to prepare, common disputes and report checks for this injury type.
Multiple impairments
Multiple injuries and combined impairment
How assessment works, evidence to prepare, common disputes and report checks for this injury type.
What every WPI file should check
- the accepted injury and body system being assessed
- whether maximum medical improvement has been reached
- the material sent to the assessor, including imaging, specialist records and capacity certificates
- whether pre-existing conditions, degeneration or non-work causes are deducted and explained
- what the percentage changes for Section 66, weekly payments, medical expenses or work injury damages strategy