OBJECTIVES: To determine the budget impact of everolimus (in combination with letrozole/anastrozole) as a second-line treatment for ER+ HER2-negative advanced and metastatic breast cancer in postmenopausal women in Kazakhstan. METHODS: A cumulative cohort model was developed to estimate the five-year costs associated with introducing everolimus to the Kazakh healthcare system, with two scenarios: “with everolimus” and “without everolimus”. Treatment-specific PFS and OS data were extrapolated from trial data using a Weibull function. It was assumed that data from the BOLERO-2 trial (everolimus+exemestane vs exemestane alone) were representative of everolimus+letrozole/anastrozole and letrozole/anastrozole used in the model.  Per-patient drug, health state, adverse event costs were calculated. The per-patient costs were multiplied by the number of patients expected to receive each treatment according to predicted market share, which was split between everolimus+letrozole/anastrozole, letrozole/anastrozole alone, chemotherapy and tamoxifen. RESULTS: The within-trial data from BOLERO-2 reported 17 month OS of 74.7% and 67.6% for everolimus+exemestane and exemestane alone, respectively. The utilities reported in BOLERO-2 (data available up to week 78) were 0.67 and 0.70 for everolimus+exemestane and exemestane alone, respectively. The five year results demonstrate that the introduction of everolimus leads to a 12% increase in drug costs, a 2% reduction in pre-progression health state costs, a 1% increase in post-progression health state costs and a 2% reduction in adverse event costs.  The net result is a 2% increase in total costs, from T16.97 billion to T17.389 billion over a period of five years. CONCLUSIONS: The analysis estimated that, if everolimus were to be introduced to the Kazakh healthcare market for the treatment of ER+ HER2- advanced breast cancer, there would be a small impact upon overall healthcare expenditure. An increase in drug acquisitions costs was largely offset by a reduction in other healthcare costs due to improved disease management.