SpaceX has about 6 recovered boosters which will be reused. Most will be reused and not recovered in the next several launches.

SpaceX ic counting on Block 5 to succeed with increased reusability and for faster relaunching. If any design or manufacturing flaws are discovered in the first several Block 5 Falcon 9s, or if Block 5 is less reusable than SpaceX then SpaceX could have delays in its launch schedule.

The first Block 5 Falcon 9 first stage is on the test stand at their McGregor, Texas test facility.

The maiden flight is planned for April 2018, with the Bangabandhu-1 satellite.