This study employed a constitutive (CCO) communication approach to advance the dynamic concept of communication maturity for the purpose of theorizing, analyzing, and developing communication value on an organizational level. A literature review resulted in six theoretical areas related to communication maturity: understanding, function, organization, prerequisites, competence and practices including assessments of communication. These were analyzed in a qualitative comparative case study including 85 key stakeholders from eleven organizations. Findings illustrated the relevance of the theoretical areas to stakeholders' perceptions of their respective organizations' communication maturity. A first version of a Communication Maturity Index including four levels of maturity; immature, emerging, established, and mature is proposed. Based on the qualitative analysis, organizations' communication maturity levels varied from emerging to mature. Findings of this study are limited to participating organizations and interviewed stakeholders. The CMI can be further developed in quantitative studies to investigate the constitutive role of communication in organizations and to be used in practice to develop higher levels of communication maturity.