End-stage renal disease patients undergoing dialysis have specific characteristics compared to other patients. Whether their mode of dialysis is hemodialysis or peritoneal dialysis, they should maintain this treatment for life, Because discontinuation of dialysis results in serious consequences and threaten life.  Life-time duration of dialysis treatment can be affected by many factors. Socioeconomic status influence medical decision in choosing among treatment modalities and prescription decision making. Currently, Korea holds two different insurance type on patients according to their socioeconomic status, that is National health insurance (NHI) vs medical aid program (MAP). Previous studies have shown health insurance type affects patients’ outcome indicators.  This study aims to research the impact of health insurance type on hospitalization and treatment outcomes in dialysis patients using data on hemodialysis patients enrolled in the KSN ESRD registry.