<p>Assessing client needs is integral to improving outcomes in community mental health services, yet tools to evaluate the extent to which needs are met remain underutilized. This study examines patterns of met needs and disparities across sociodemographic groups using the Ontario Common Assessment of Need (OCAN), a standardized tool adapted from the Camberwell Assessment of Need (CAN) and widely implemented in Ontario, Canada. Specifically, we applied the Ontario Modified Met Needs Index (OMMNI), a ratio-based metric, to measure the extent to which identified needs were addressed over the course of care. Using longitudinal OCAN data from 4,537 clients engaged in assertive community treatment, case management, early psychosis intervention, and supportive housing programs, we calculated OMMNI scores based on both staff- and client-completed assessments. Results showed that 74% of staff-identified needs and 72% of client-identified needs were met or remained met. At the domain level, safety-related needs had the highest rates of being met (≥ 85%), while sexual expression, intimate relationships, company, daytime activities and psychological distress were least consistently addressed (&lt; 70%). Disparities in staff assessments were observed for younger clients and those with unspecified service languages, while disparities in client assessments were noted for clients identifying as transgender or non-binary. These findings underscore variability in addressing diverse client needs, highlighting opportunities to enhance person-centered care. The OMMNI holds potential as a practical tool for measuring met needs, identifying disparities, informing service planning, and supporting quality improvement. Further validation is needed to ensure its applicability across populations and service contexts.</p>