The status of the construction and installation of CMS is reviewed. All big mechanical pieces have been assembled in the surface hall SX5 (except the 2nd hadronic endcap calorimeter, HE+1, to be assembled this autumn). A full test of the magnet on the surface will start in mid-2005. Awaiting delivery of the underground caverns, installation and commissioning of the hadron calorimeter and of the muon system has started in SX5. The assembly sequence followed by CMS (03) is based on the completion of the full CMS detector, minus the staged items (ME4/1 and ME4/2, some RPC chambers at low angles, 50 % DAQ online farm, 3rd forward pixel disks), in time for collisions in mid-2007.