The proliferation of complex service systems raises new challenges for service design and requires new methods. Multilevel Service Design (MSD) is presented as a new interdisciplinary method for designing complex service systems. MSD synthesizes contributions from new service development, interaction design, and the emerging field of service design. MSD enables integrated development of service offerings at three hierarchical levels: (a) Designing the firm’s service concept with the customer value constellation of service offerings for the value constellation experience; (b) Designing the firm’s service system, comprising its architecture and navigation, for the service experience; and (c) Designing each service encounter with the Service Experience Blueprint for the service encounter experience. Applications of the MSD method are described for designing a new retail grocery service and for redesigning a bank service. MSD contributes an interdisciplinary service design method that accommodates the cocreative nature of customer experiences and enables experience integration from the design of the service concept through the design of the service system and service encounter.