An extension (20) for a catheter assembly (10) may include a distal end and a proximal end. The distal end may include one or more cantilever arms (= 26) and an insertion feature (24) spaced apart from the cantilever arms. The insertion feature may be configured to insert into a lumen of a catheter adapter (12) to provide a fluid connection between the catheter adapter and the extension. The one or more cantilever arms may be configured to engage in a snap-fit with the catheter adapter. The proximal end of the extension may include a female luer fitting (30).