353 Background: Postoperative chronic kidney disease (PCKD), defined as a glomerular filtration rate of < 60mL/min/1.73m2, is a recognized adverse outcome after extirpative therapy for small renal masses (SRM, ≤ 4cm). We quantified the long-term economic and clinical costs of PCKD following radical and partial nephrectomy for the management of SRM. Methods: Using a Markov model, we evaluated open and laparoscopic approaches for radical and partial nephrectomy in the treatment of SRMs. The base case was a 65-year old healthy individual with a unilateral SRM and normal renal function. We used a 3-month cycle length, lifetime horizon, societal perspective, and 3% discount rate. The costs, quality of life adjustments, and transition probabilities were estimated from the literature, Medicare, and expert opinion. Health outcomes were measured in quality-adjusted life-years (QALY) gained and costs in 2008 U.S. dollars. The model was tested with sensitivity analyses. Results: The average discounted lifetime outcomes are listed in the Table. There were minimal differences between the open and laparoscopic approaches. PCKD led to a substantial increase costs and decrease in health outcomes. The impact of PCKD was indirectly associated with age. Conclusions: Partial nephrectomy provides cost-savings and improved health outcomes compared to radical nephrectomy in the management of patients with SRMs. Both procedures incur significant economic and clinical costs due to the development of PCKD. A discussion about the potential for PCKD should be incorporated into the informed consent for surgical treatment of SRMs. [Table: see text] No significant financial relationships to disclose.