The present disclosure is directed to an over-the-needle (OTN) catheter assembly having an expandable catheter. More specifically, the OTN catheter assembly includes a catheter having an expandable body with a proximal end and a distal end coaxially mounted onto a needle. The body defines a lumen extending from the proximal end to the distal end. Further, the body is expandable between a compressed length and an expanded length. The needle is configured within the lumen of the catheter and has a first length. The first length is longer than the compressed length of the catheter and shorter than the expanded length of the catheter. In addition, the body of the catheter is configured to expand from the compressed length to the expanded length when heat is applied to the catheter such that the distal end of the catheter extends past a distal end of the needle.
