Background/Objective <p>Idiographic patient-reported outcome measures (I-PROMs) have been shown to be an engaging and meaningful way of collecting therapeutic outcomes in healthcare, but no such tool currently exists in adult aural rehabilitation. This paper describes a new I-PROM, the Individual Management Plan Outcome Score (IMP-OS) that was developed in a North Wales audiology service and aims to assess its psychometric properties.</p> Methods <p>IMP-OS was compared to two existing condition-specific patient reported outcome measures (PROMs) for convergent validation, and a generic health-related quality of life PROM for divergent validation. Test–retest reliability was also assessed, and normative data were derived, leading to the creation of clinical interpretation recommendations. Convergent, divergent validation and normative data were based on sample A (59 adults) and for test–retest, sample B (15 adults).</p> Results <p>IMP-OS was significantly correlated with some condition-specific PROMs, but not with the generic PROM. It had a moderate-excellent test–retest reliability. Normative data showed that scores below 50 would suggest further clinical intervention is warranted, and should guide further therapeutic discussions with the patient.</p> Conclusions <p>IMP-OS is the first I-PROM in audiology to be psychometrically verified using international best-practice. It has been shown to reflect aspects of hearing-related outcomes that are important to patients and can be easily integrated into current clinical practice thus helping guide patient-centred care.</p>