Stewart v Kirk [2026] ACTSC 33
Key Takeaways
- The 10% WPI threshold under s 239(1)(a) of the Motor Accident Injuries Act 2019 (ACT) (the Act) can only be satisfied by a Whole Person Impairment (WPI) assessment conducted by the independent medical examiner (IME) appointed by the IME provider. It cannot be satisfied by a private medical examiner, even where they also happen to be an independent medical examiner for the purposes of the Act.
- A second WPI assessment obtained from a private medical examiner serves only a limited purpose within the statutory scheme: it provides the injured person with an opportunity to persuade the original independent medical examiner to increase the assessment. It does not determine whether the WPI threshold is met.
- The decision confirms that the statutory scheme confers authority to determine WPI in the independent medical examiner appointed by the IME provider at the insurer’s request. Any challenge to that determination must be pursued by way of administrative review.
- This is a significant outcome for insurers. It confirms that the common law damages gateway cannot be circumvented by obtaining a favourable private WPI assessment, regardless of the qualifications of the private examiner.
Background
On 2 July 2020, Jacquelyn Stewart was injured in a motor vehicle accident when Nigel Kirk drove his car through a red light, colliding with Ms Stewart’s vehicle. The insurer, Insurance Australia Limited trading as NRMA Insurance, accepted liability for defined benefits under the Motor Accident Injuries Act 2019 (ACT) (the Act) from the date of the accident.
Ms Stewart sought to bring a common law claim for damages. Section 239(1)(a) of the Act imposes a precondition: the injured person must have been assessed as having a Whole Person Impairment (WPI) of at least 10% as a result of the accident. How that assessment is obtained, and by whom, was the central issue in these proceedings.
The WPI Assessment Process
The Act creates a structured regime for WPI assessments. The insurer refers the injured person to an authorised IME provider, who appoints an independent medical examiner to conduct the assessment. Medico Legal Consultants of Australia (MLCOA) is currently the only authorised IME provider in the Territory.
Ms Stewart was referred to MLCOA for separate WPI assessments of her physical and psychological injuries. Dr Seevnarain assessed her physical injuries at 0% WPI and Dr Spear assessed her psychological injuries at 5% WPI. Accordingly, the insurer notified Ms Stewart that she fell below the 10% threshold, and offered quality of life benefits of $7,460.
Exercising her right under s 158(2) of the Act, Ms Stewart obtained second WPI assessments from private medical examiners. Dr Takyar assessed her psychological injuries at 15% WPI, and Dr Ridhalgh assessed her physical injuries at 14% WPI. Although Dr Ridhalgh also held the status of an independent medical examiner for the purposes of the Act, he assessed Ms Stewart as a private medical examiner and was not appointed by MLCOA.
Ms Stewart provided her two private reports to the insurer as permitted under s 158(5). The insurer forwarded them to MLCOA, who submitted them to the original independent medical examiners for review. Both original examiners affirmed their assessments. Accordingly, as far as the independent medical examiners were concerned, Ms Stewart did not meet the 10% threshold.
The Dispute
Ms Stewart served a Notice of Claim and sought a compulsory conference under s 258 of the Act. The insurer rejected the Notice of Claim and refused to attend the conference, maintaining that the precondition for bringing a court proceeding (a WPI assessment of at least 10%) had not been met.
Ms Stewart brought proceedings before the Supreme Court. The insurer responded by seeking to have Ms Stewart’s application dismissed under s 239(1)(a).
The Central Issue
The core question before McCallum CJ was deceptively simple: who is to make the WPI assessment that engages the s 239(1) threshold?
Section 239(1)(a) requires that the injured person ‘has been assessed’ as having a WPI of at least 10%. The provision is expressed in the passive voice, creating an ambiguity as to whether the threshold can be satisfied by any assessment – including one from a private medical examiner who happens to also be an independent medical examiner – or only by the assessment of an IME appointed by the IME provider.
Ms Stewart contended that, because Dr Ridhalgh is an independent medical examiner for the purposes of the Act, his assessment of 14% WPI – even though made in his capacity as a private medical examiner – was sufficient to satisfy the threshold. Put simply, the plaintiff argued the words ‘has been assessed’ were broad enough to capture an assessment by any person who is in fact an independent medical examiner, regardless of the capacity in which the assessment was made.
The insurer contended that the words ‘has been assessed’ refer to the final assessment of the independent medical examiner appointed by the IME provider, which is only reached at the conclusion of the comprehensive statutory process.
The Court’s Analysis
Statutory Context and the Role of the Private Medical Examiner
McCallum CJ undertook a detailed analysis of the statutory scheme, applying orthodox principles of statutory construction as recently reiterated by the High Court in ENT19 v Minister for Home Affairs [2023] HCA 18; 278 CLR 75. Her Honour’s analysis focused on the text, context and purpose of s 239 within the broader statutory regime.
The Court traced the pathway for a quality of life benefits application through Division 2.6 of the Act, noting that the process begins with a mandatory referral by the insurer to an authorised IME provider for a first WPI assessment (s 137(4)). Different provisions then apply depending on the WPI assessed: sections 154 through 157 prescribe the insurer’s obligations based on whether the WPI is less than 5%, between 5% and 9% (inclusive), or 10% or more.
Critically, Her Honour examined the role of the second WPI assessment within this scheme. The right to obtain a second assessment from a private medical examiner is a contingent right which only arises after the insurer has obtained the first assessment and served the WPI reports with an offer (s 155(3) of the Act). The second assessment is not binding on either party. If the injured person chooses to provide it to the insurer, the insurer may (but is not required to) forward it to the original independent medical examiner for review under s 159.
The Court found that the independent medical examiner’s review under s 159 presents a binary choice: affirm the original assessment or increase it. The original examiner is under no obligation to accept the second assessment or to increase to at least 10%. The insurer is not bound by the second assessment, but is bound by any upward revision made by the original independent medical examiner (s 159(6)).
Contextual Analysis
McCallum CJ accepted that, while the text of s 239 was capable of supporting Ms Stewart’s construction on a superficial reading, the plaintiff’s argument failed when the provision was read in context. Her Honour noted several key contextual indicators:
First, the statutory scheme confers the authority to determine WPI on the independent medical examiner appointed by the IME provider. The private medical examiner’s role within Division 2.6.3 is limited: it is confined to providing an opportunity for the injured person to persuade the original examiner to revise their assessment upward. It is not an independent pathway to satisfying the threshold.
Second, the insurer pointed to the absence of any reference to a private medical examiner in s 159, which governs the review process. It is the affirmation or confirmation of the independent medical examiner that binds the insurer, not the assessment of a private examiner.
Third, and more compellingly, Her Honour observed that acceptance of the plaintiff’s construction would produce an untenable result: the WPI assessment of the private medical examiner would bind the insurer solely for the purpose of determining whether the statutory precondition for an award of damages was met, yet have no binding effect for any other purpose. By contrast, the statutory scheme contemplates that the final WPI assessment will be made by the independent medical examiner initially appointed by the IME provider.
Her Honour also noted that, while the legislature could have easily achieved the construction contended for by the plaintiff by adopting different language, the constructional choice raised by the plaintiff’s argument appeared unlikely to have been considered by the drafters. The subsequent amendment to
s 239(1)(a), which now expressly requires that an assessment be conducted by an independent medical examiner under Division 2.6.3, reinforced this conclusion, though her Honour acknowledged the amendment might equally have been intended to clarify what was always intended.
Decision
McCallum CJ accepted the insurer’s construction. The fact that Dr Ridhalgh is an independent medical examiner does not elevate his assessment to the place of an assessment of an independent medical examiner appointed by the IME provider to make the first WPI assessment. Ms Stewart’s originating application was dismissed.
In light of this conclusion, it was not necessary for the Court to determine a separate argument raised by the insurer based on s 51 of the Civil Law (Wrongs) Act 2002 (ACT).
Practical Implications
This is the first occasion on which the Supreme Court has considered the interplay between IME assessments and private medical examiner assessments for the purpose of the s 239 WPI threshold. The decision provides important clarity for insurers and plaintiff lawyers operating under the Act.
For insurers, the decision confirms that the 10% WPI gateway for common law claims is firmly within the control of the statutory IME process. An injured person cannot bypass that process simply by obtaining a favourable assessment from a private examiner who also holds IME status. The integrity of the threshold, and the corresponding ability of insurers to manage their exposure to common law claims, is preserved.
The decision underscores the critical importance of the initial IME assessment and the review process under s 159. Where the first WPI assessment falls below 10%, the plaintiff’s most effective avenue remains persuading the original IME to increase their assessment on review, rather than relying on a private assessment to independently satisfy the threshold. Alternatively, administrative review of the IME determination may be pursued.
Further information
This article was written by Principal Lawyer Angel Li and Special Counsel Jesse Iliopoulos. For further information or advice on any related matters please contact Angel or Jesse.
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