For lunar missions it was fired twice: first for Earth orbit insertion after second stage cutoff, and then for translunar injection (TLI).

At the same time, it was decided to create the C-IB rocket (Saturn IB) that would also use the S-IVB as its second stage and could be used for testing the Apollo spacecraft in low Earth orbit.

NASA was working on acquiring 4 additional 200-series stages (as part of 4 new Saturn IB rockets, SA-213 to 216), but funding never materialized and the order was canceled in August 1968 before S-IVB hardware was assembled.

On the 500 series this was reduced to two, and two small Auxiliary Propulsion System (APS) thruster modules were added as ullage motors for restarting the J-2 engine and to provide attitude control during coast phases of flight.

Empty mass was 10,000 kilograms (22,000 lb)[3][4] Attitude control was provided by J-2 engine gimbaling during powered flight and by the two APS modules during coast.

From Apollo 13 onward, the S-IVB stages were crashed into the Moon to perform seismic measurements used for characterizing the lunar interior.