CMS-Flow is a coupled time-dependent circulation, sediment transport and morphodynamic model based on the numerical solution of the mass, momentum and transport equations on a Cartesian (quad-tree) grid network with both explicit and implicit solvers. It has been developed and is currently supported under the Coastal Inlets Research Program (CIRP) conducted at the U.S. Army Engineer Research and Development Center (ERDC), Coastal and Hydraulics Laboratory (CHL). The model's primary function is to support multi-disciplinary research teams and conduct practical projects at coastal inlets. CMS-Flow has been designed with a relatively simple code structure which allows for rapid development and inclusion of new sediment transport algorithms, while always being accessible to the general modeling community, including both USACE and commercial users. Today, CMS-Flow is an integral component of the CIRP, providing technology for simulating hydrodynamics, waves, sediment transport and morphology for short and long timeframes in coastal inlets, adjacent beaches, navigation channels and bays.