Rehabilitation services should be available worldwide for every person who has problems with functioning. Thus, rehabilitation services must be organized at all levels of healthcare, from the community, through primary care to general and specialized hospitals. Rehabilitation services are needed along the continuum of care: from acute, through post-acute to the chronic phase. In order to plan these services a classification system is needed to describe, in a uniform way, the different types of services and their characteristics. The second version of the International Classification System for Service Organization in Rehabilitation (ICSO-R 2.0), described in this paper, comprises 9 categories describing the provider of the service and 14 categories concerning service delivery. ICSO-R 2.0 will enable improved description of available service organization and facilitate the identification of rehabilitation service provision worldwide. Thus, the updated ICSO-R 2.0 will benefit all persons in need. Objective: To develop a revised version of the International Classification of Service Organization in Rehabilitation (ICSO-R). Design: Qualitative study. Methods: The revision was based on testing the first version of the ICSO-R; 2 discussion rounds invited by the ICSO-R working group of the Standardized Rehabilitation Reporting Subcommittee of the World Health Organization Liaison committee of the International Society of Physical and Rehabilitation Medicine, and a call for corrections from a group of international experts. Results: The resulting ICSO-R 2.0 version is composed of 2 dimensions (formerly 3); the Provider dimension and the Service delivery dimension. The categories of the Funding dimension from the first version of ICSO-R were incorporated into each of the other dimensions. The Provider dimension now consists of 9 categories and the Service delivery dimension consists of 14 categories. Subcategories have been added to 7 categories: governance/leadership, funding of provider, target groups, location of service delivery, setting, rehabilitation team, and funding of service delivery. Conclusion: This updated version of ICSO-R provides a prerequisite for rehabilitation service organization assessment and implementation projects, reporting of contextual influences in clinical trials and many other aspects. In addition, ICSO-R 2.0 can be used for several purposes, e.g. to analyse and compare the provision of rehabilitation services in health systems and to support the quality management of rehabilitation services. However, the development of value sets for each (sub)category and further validation studies are still needed.