The present invention is a simple-to-use IV placement assist device with an added safety feature. A catheter advancer is slidably integrated with a base to guide advancement of a catheter linearly along the insertion path of the needle and catheter. A safety feature is engaged by a movable component moving from a first position to a second position, such movable enabling relative movement between the base and catheter advancer and/or catheter assembly, rotation of the needle about its length axis, and/or minor advancement of the catheter assembly to sheath the tip of the needle. The IV placement assist device stabilizes and guides the critical needle insertion and catheter advancement steps of a complication-prone and very common procedure.