After the high-luminosity upgrade of the LHC (HL-LHC), the instantaneous luminosity will increase to unprecedented values of $5-7 \times10^{34}\,\mathrm{cm^{-2}s^{-1}}$. In order to cope with these conditions the whole CMS silicon tracker detector will be replaced. This presentation describes the Phase-2 upgrade of the inner pixel system. The new inner pixel detector will be composed of three sub-detectors: the barrel detector (TBPX) consisting of four concentric cylindrical layers, the forward detector (TFPX) consisting of eight small disks on each end, and the end-cap detector (TEPX) with four large disks on each end.