The Facility for Rare Isotope Beams (FRIB) is a high power heavy ion accelerator facility presently under construction and commissioning at Michigan State University in USA. Its driver linac is designed to accelerate all stable ions to energies above 200 MeV/u with beam power of up to 400 kW. For the FRIB linac, phased commissioning of 7 phases is adopted and the beam commissioning of upstream segments have been started since 2017 in parallel with the construction in downstream segments. The beam commissioning for 3 of 7 phases have been completed successfully. At the third phase of beam commissioning, four ion species of Ar, Ne, Kr, and Xe have been accelerated to a higher energy than 20 MeV/u with 15 Quarter Wave Resonator (QWR) cryomodules. At this stage, the FRIB linac has become the world's highest energy Continuous Wave (CW) hadron linac. At the next phase of beam commissioning scheduled after the readiness review in March 2020, we aim at accelerating these heavy ion beams to about 200 MeV/u using the 15 QWR cryomodules and 24 Half Wave Resonator (HWR) cryomodules. Operations for scientific users and beam power ramp up towards 400 kW are expected to start as planned in 2022. In parallel with the commissioning, research and development for future upgrades are also progressing.