OBJECTIVES: To assess the cost-effectiveness between two non-calcium binders, lanthanum carbonate (LC) and sevelamer hydrochloride (SH), in end-stage renal disease (ESRD) patients previously treated with calcium-based binders. METHODS: A Markov model was developed to estimate incremental costs for three health outcomes: 1) quality-adjusted life years (QALYs), 2) Life-years saved (LYS) and 3) percent who successfully met serum phosphorus (SP) level goals (3.5-5.5mg/dl) between the two non-Ca binders. The model incorporated patient-level data from a randomized head-to-head crossover study which compared the reduction of SP using fixed doses of LC for 4 weeks.  For this analysis the model included patients previously treated with calcium-based binders.  The ‘intent-to-treat’ (ITT) population and the ‘completer’ population were assessed.  Baseline risks of cardiovascular disease (CVD), overall mortality, and CVD mortality were derived from a large US epidemiological study. Utilities, costs and relative risks of CVD were derived from published sources. Patient outcomes were modeled for 10 years, and incremental cost-effective ratios (ICERs) were calculated for LC relative to SH. Clinical and economic outcomes were discounted at 5% per year. Deterministic and probabilistic sensitivity analyses (PSA) were performed to test the model robustness. RESULTS: Using clinical results of patients previously treated with a calcium-based binder, for the ITT population, the ICERs were $24,724/QALY, $15,053/LYS and $6,700/additional success (i.e., SP goal achievement), respectively.  For patients who completed the randomized controlled trial, the ICERs of LC compared with SH were $15,285/QALY, $9,337/LYS and $8,265/additional success respectively. The PSAs indicated a 61.9% and 85.8% probability of LC being cost-effective at the $50,000/QALY threshold, for the ITT population and completer populations, respectively.  Sensitivity analyses support the robustness of the model results. CONCLUSIONS: LC is a cost-effective strategy compared to SH in ESRD patients previously treated with calcium-based binders.