TheTsionou, D. CMS Collaboration is designing a new high granularity endcap calorimeter, HGCAL, to be installed as a replacement endcap calorimeter for the High Luminosity LHC era, later this decade. This sampling calorimeter will have approximately six million silicon sensor cells and four hundred thousand scintillator tiles readout with on-tile silicon-photomultipliers. After prototypes and past test beams, the module hardware design has been finalised and CMS is preparing for the mass assembly process. We present the status of the silicon modules for the HGCAL as well as the assembly process.