Abstract: The present invention is a simple-to-use access device with a safety feature. A catheter advancer (30) is slidably and rotatably integrated with a base (10) to guide advancement of a catheter (50) linearly along the insertion path of a needle (60) and catheter (50). The catheter advancer (30) engages the base (10), catheter (50) and needle (60) and both sequences and delimits relative movement between the base (10), catheter advancer (30), catheter assembly (50) and needle (60). The access device stabilizes and guides the critical needle insertion and catheter advancement steps of a complication-prone and very common procedure.