This study focuses on the organisations in the people care sector (OPCs), encompassing a broad spectrum of activities ranging from essential healthcare services to various aspects of daily living support. Sustainability in OPCs encompasses multiple dimensions aimed at ensuring the long-term viability, efficiency, and effectiveness of services provided to vulnerable populations. Given the critical role of digital technologies in enhancing the operational efficiency within such organisations and their sustainability, it becomes imperative to gauge their digital maturity levels. To establish a robust framework for assessing the digital maturity of OPCs, we identified 29 factors grouped into five clusters that encapsulate various dimensions of digital readiness that directly influence the sustainability of OPCs. We employed the SNAP methodology to ascertain the relative significance of these factors and clusters. Furthermore, each factor was articulated through the lens of digital maturity using the rubrics approach, offering a nuanced understanding of the OPCs’ digital readiness across four distinct levels. Experts from the people care sector, IT, and multi-criteria decision-making contributed invaluable input during the instrument’s development phase. Theoretical validation of the instrument involved focus group discussions with domain experts, while practical validation entailed applying the instrument to real-world case studies. The instrument enables OPCs to assess their digital maturity levels, providing valuable strategic planning and decision-making insights. Furthermore, the instrument can serve as a roadmap for identifying areas ripe for digital transformation and weak points, facilitating continuous improvement and future readiness. The quantification of the digital maturity of the OPC enables the OPCs to rank at the cluster maturity level and overall maturity level. Overall, this instrument represents a significant step towards enhancing digital maturity assessment within the OPC sector, contributing to its evolution and adaptation in the digital age, and enabling the OPCs’ sustainability.