The CMS inner tracker -- transition from LHC Run~I to Run~II and first experience of Run~II

The CMS silicon pixel and strip trackers provide high efficiency charged particle reconstruction and superb momentum resolution over three decades in energy, and thus play a key role in the CMS physics program. The readiness of the silicon tracking detectors for LHC Run~II data taking is presented in this paper. In light of improvements to the tracker operating environment and repairs of defective pixel channels during the first LHC long shutdown, the Run~II tracker is expected to have a larger yield of active channels than during Run~I and to continue to perform well at the foreseen luminosities.