Geoscience model infrastructure provides architecture and services for building physics-based numerical models and combining multiple models into a coupled system. Examples of model infrastructure are software libraries and frameworks that provide data structures and functions for parallel data transfer and grid interpolation, define a common interface for model components, manage a model's control flow, abstract details of parallel programming, or provide supporting capabilities such as configuration management and file I/O. The special issue of GMD is dedicated to exploring all aspects of model infrastructure integration and interoperability. Model infrastructure integration is the software engineering process of adopting an infrastructure package into a numerical model's codebase, to address new scientific requirements, enable interoperability with other models, or to improve a model's performance. Model infrastructure interoperability is required whenever multiple infrastructure packages must interact in some way in a coupled system, for example, to couple model components that originate from different scientific communities into a single cohesive system. Topics of interest for this issue include but are not limited to the following: the design and implementation of geoscience model infrastructure software; experience reports on integrating infrastructure into models; modelling systems that span scientific communities; framework interoperability, metadata and semantic mediation; performance on emerging hardware platforms; configuration and build management; and tools that support infrastructure integration, code refactoring, verification, or debugging.