Abstract: A catheter adapter may include a distal end, a proximal end, an inner surface extending through the distal end and the proximal end and forming a lumen, and a side port forming a side port pathway through a sidewall of the catheter adapter and in fluid communication with the lumen. The catheter assembly may include a catheter extending distally from the distal end of the catheter adapter. The catheter assembly may include a septum disposed within the lumen proximal to the side port pathway. The catheter assembly may include one or more features to facilitate flushing of the catheter assembly: a diameter of the side port may increase in a distal direction; a portion of the inner surface proximal to the catheter and distal to the septum may include multiple grooves; the side port pathway may include a non-cylindrical portion; an insert; a rotation element; and a pivot element.