A fenestration over-the-needle catheter assembly which includes a catheter (10) with a catheter body (20). The catheter body (20) has a projection (26) which extends in an axial direction from the distal end (14) of the catheter. The projection (26) may have a point of connection (28) to the catheter body (20) such that the projection (26) can be transitioned into a closed position, covering an opening (24) in the distal end (14) of the catheter. The projection (26) is configured to interact with a needle (18) which has been inserted into a catheter lumen and extends through the opening (24) in the distal end, such that the projection (26) is in an open position when the needle (18) is extended through the opening (24) in the distal end (14) and is in a closed position when the needle is (18) withdrawn into the lumen or removed from the catheter.
