The purpose of this paper is to propose an approach to lean service innovation. The knowledge gap relates to three specific challenges of service innovation: early identification of the core customer value with business potential, in-depth understanding of customer value for new or potential customers, and discovery and utilization of latent customer needs. As a result, this article introduces a model of lean service innovation. The model focuses on the process rather than on single cocreation methods. The model shows how a new service can iteratively be developed through several improvement rounds into a final service, and each round increases the company's understanding of customer value and capability to better integrate resources for this. Both the theoretical domain and the application of service-dominant logic can be extended with the lean service innovation approach introduced here. It shows the process of in-depth learning with customers and the rapid prototyping of a service. It facilitates early identification of the core customer value with business potential in the innovation process, identification of customer value for new or potential customers, and discovery and utilization of latent customer needs in innovation. It illustrates repeated experimentation and improvement of service with customers and ultimately supports the implementation of service-dominant logic in innovation.