Section 66 Lump Sum Compensation Guide NSW

The legal threshold is not the assessment method

The assessor determines WPI using the NSW Guidelines. The legislation then determines whether the result meets the Section 66 threshold and which compensation scale applies. Surgery, time off work, pain severity and an insurer's acceptance of liability do not create an automatic WPI percentage.

For how Section 66 fits with weekly payments, treatment and disputes, read the NSW workers compensation claim guide.

Thresholds for most current claims

Physical injury

Permanent impairment must be greater than 10% WPI, commonly expressed as 11% or more. This is a statutory threshold, not a rounding rule.

Primary psychological injury

Permanent impairment must be at least 15% WPI. Secondary psychological impairment is not assessed for Section 66 compensation.

Claims outside the general scheme

Police officers, paramedics, firefighters, coal miners, volunteers, dust disease claims, pre-2002 injuries and some historical claims can be governed by different provisions. The threshold should be checked against the worker category and injury date.

How multiple impairments are treated

Section 65 requires impairments from injuries arising from the same incident to be assessed together. Within a physical assessment, permitted values are converted to WPI and combined using the Combined Values Chart, not ordinary addition. Overlapping impairment cannot be counted twice.

Physical and primary psychological impairment are not combined. Section 65A provides that Section 66 compensation is paid for whichever produces the greater amount, not both. The medical and legal reasoning should be shown separately.

How a NSW permanent impairment percentage is built

For a Section 66 lump-sum claim, a valid WPI opinion should show a chain from the accepted diagnosis to the applicable NSW method, measured findings, any regional conversion, any permitted combination and any pre-existing impairment deduction. This matters when deciding whether the medical percentage supports a Section 66 claim and whether the accepted injuries are complete; a report that only records an examination does not explain the percentage.

1. Confirm the body system and diagnosis

Spine, upper limb, lower limb, hearing, respiratory, skin, neurological and primary psychiatric impairments use different methods. The referral should identify the accepted injury and any consequential physical condition being assessed.

2. Decide whether maximum medical improvement has been reached

In a Section 66 lump-sum claim, NSW Guidelines paragraph 1.15 requires a well-stabilised condition unlikely to change substantially in the next year, with or without treatment. If adequate treatment could still materially improve the assessed condition, paragraph 1.16 requires the timing to be deferred.

3. Apply the correct NSW/AMA method and measure the required findings

When preparing a Section 66 lump-sum claim, the NSW Guidelines prevail over AMA5. The body system determines whether the assessor measures DRE clinical features, active joint movement, nerve sensory and motor loss, audiometric thresholds, pulmonary function, skin criteria, neurological function or the six PIRS domains.

4. Convert regional values and combine only where permitted

For a Section 66 lump-sum claim, a digit, hand, upper-extremity, foot or lower-extremity value may require conversion before it becomes WPI. Permitted physical WPI values use the AMA5 Combined Values Chart rather than ordinary addition. For example, 20% WPI combined with 10% WPI is 28%, because the second value applies to the remaining 80%. This arithmetic only demonstrates the chart.

5. Explain deductions and excluded methods

In a Section 66 lump-sum claim, a pre-existing diagnosis does not justify an automatic deduction. Section 323 first requires a finding that a previous injury, pre-existing condition or abnormality actually contributed to the assessed degree of permanent impairment. Only the proportion due to that earlier impairment is deducted. AMA5 Chapter 18 pain is excluded; pain is ordinarily addressed through the underlying diagnosed condition. Primary psychiatric WPI is assessed separately and cannot be combined with physical WPI, secondary psychiatric impairment is not assessed for WPI, and NSW excludes using ADL to alter upper- or lower-extremity ratings.

Worked illustration: a pre-existing impairment deduction

In this illustration of a Section 66 lump-sum claim, assume the body-system method produces 20% WPI and the assessor first finds that an earlier condition contributed to that assessed impairment. If the extent of that contribution is too difficult or costly to determine, section 323 permits an assumed deduction of one tenth of the impairment unless that assumption is at odds with the available evidence. One tenth of 20 is 2, so the arithmetic produces 18% WPI after deduction.

The threshold finding matters. In Walton v State of New South Wales (Hunter New England Local Health District) [2026] NSWSC 824, the Court explained that the mere existence of a condition, or evidence that it caused pain, is not enough. The condition must have increased or contributed to the degree of impairment being assessed before the one-tenth assumption can be used. The figures above explain deduction arithmetic only and do not predict an individual result.

Read the Walton section 323 case note or section 323 in the current 1998 Act.

Sources for this framework

Sources used for a Section 66 lump-sum claim: NSW Workers Compensation Guidelines for the Evaluation of Permanent Impairment, Fourth Edition, paragraphs 1.6-1.24 and 1.27-1.31; AMA5 Chapters 1-2 and the Combined Values Chart at pages 604-606. NSW uses AMA4 Chapter 8 for the visual system. The body-system guides identify the additional paragraph and table where relevant.

Choose the body-system permanent impairment guide for the measurements, conversion steps and verified examples relevant to the injury.

Back impairment and the 5% amount increase

Section 66 includes a specific rule for permanent impairment of the back. Where it applies, the compensation amount calculated for the back impairment is increased by 5%. The provision does not convert, for example, 12% WPI into 17% WPI. Threshold questions still use the assessed WPI.

Current process

Permanent impairment assessments from 1 July 2026 to mid-2027

NSW is in an interim period. Separate examinations arranged by the worker and insurer can still occur, but an interim assessment must be performed by an assessor on SIRA's register. Liability for the injury must have been determined before an interim assessment is made.

Independent legal advice is compulsory

A worker must receive independent legal advice about the full legal implications before being seen by a permanent impairment assessor. Advice is also required before entering an impairment agreement.

The assessment can affect several entitlements

The principal assessment is used across weekly payments, medical and related treatment expenses, Section 66 lump sum compensation, commutation access and work injury damages. It is not only a lump sum calculation.

Agreement or medical dispute

If the worker and insurer agree on the degree of impairment, they may enter a written impairment agreement. If they do not agree, the insurer must give written notice and either party may refer the disagreement to the Personal Injury Commission as a medical dispute, supported by medical evidence.

A further assessment is tightly restricted

A second or later assessment during the interim period requires agreement that there appears to be unexpected and material deterioration. The deterioration must be capable of increasing the impairment by at least a further 10 percentage points. Ordinary age-related deterioration does not meet that test.

Important transitional rules

If a pre-reform assessment made before 1 July 2026 has not yet been used for a Section 66 claim, SIRA says the claim must be made before 1 July 2028. No new Section 66A complying agreements can be entered from 1 July 2026. A different permanent impairment process is expected to commence from mid-2027.

The 2026 principal-assessment changes do not apply in the same way to exempt workers (police officers, paramedics and firefighters), coal miners, volunteers, dust disease claims or claims with a pre-2002 injury date.

Last reviewed 20 July 2026. Sources: SIRA worker guidance and SIRA interim assessment guidance. See also the PIC dispute guide.

A section 323 deduction needs a causal finding

An assessor cannot deduct merely because imaging shows degeneration or the worker had earlier pain. The earlier injury, condition or abnormality must have contributed to the assessed degree of permanent impairment. The deductible proportion is then assessed. If that proportion is too difficult or costly to determine, a one-tenth assumption may be used unless it conflicts with the available evidence.

Read the Walton case note for the NSW Supreme Court's explanation of this sequence.

Documents that commonly matter

the accepted injury description, injury date and liability decision;
medical evidence that maximum medical improvement has been reached;
imaging, operation reports, treating specialist material and rehabilitation records;
earlier medical records relevant to any section 323 deduction;
every impairment report relied on by either party;
the insurer's written decision or proposed impairment agreement.

Common questions

What is Section 66 compensation?

Section 66 of the Workers Compensation Act 1987 provides lump sum compensation for permanent impairment where the statutory requirements are met. The medical percentage must be assessed under the NSW Guidelines, but the entitlement and amount are legal questions under the legislation applying to the claim.

What WPI threshold applies?

For most current non-exempt claims, physical impairment must be greater than 10% WPI and primary psychological impairment must be at least 15% WPI. Exempt workers, older claims and specialised schemes may have different rules.

Can physical and psychological WPI be added together?

No. Physical and primary psychological impairment are assessed separately. For Section 66, compensation is payable for the impairment that produces the greater amount, not for both. Secondary psychological impairment is not assessed for Section 66 compensation.

Does the 5% back rule add five WPI points?

No. Where the statutory back-impairment provision applies, the legislation increases the compensation amount attributable to the back by 5%. It does not add five percentage points to the medical WPI assessment.

What happens if the parties disagree about WPI?

During the interim principal-assessment process, the insurer must give written notice if an impairment agreement is not reached. Either party may refer the medical disagreement to the Personal Injury Commission with supporting medical evidence.

Unsure whether an assessment supports a Section 66 claim?

Call (02) 7233 3661 to discuss the assessment stage, or send the report through the claim-check form.

Last reviewed 20 July 2026. This information is general in nature and is not legal or medical advice. The applicable threshold, compensation scale and transitional rule depend on the worker category, injury date and claim history.

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Section 66 lump sum compensation in NSW