Abstract Disclosure: E. Rhee: None. H. Kwon: None. S. Park: None. W. Lee: None. Background: Recently, the term non-alcoholic fatty liver disease (NAFLD) is replaced by a new term, metabolic dysfunction-associated liver disease (MASLD), with a new definition made by a modified Delphi process led by three large pan-national liver associations. In this study, we aimed to analyze the risk for chronic kidney disease (CKD) development in those with MASLD defined by the new definition and metabolic dysfunction-associated fatty liver disease (MAFLD). Methods: Among 52,606 participants (mean age 35.4 years) in the health checkup program from 2002 to 2019, in whom at least 10 health checkups were performed, after strict exclusion, 48,751 participants were enrolled and analyzed the development of CKD defined by estimated glomeruls filtration lower than 60 mL/min/1.73m2) during a median of 14.7 years of follow-up. The presence of MAFLD was defined by presence of hepatic steatosis plus one of the three criteria of overweight or obese, type 2 diabetes or presence of ≥2 metabolic risk abnormalities. MASLD was defined by presence of hepatic steatosis plus at least 1 of 5 cardiometabolic risk factors. Results: At baseline, 12,773(26.2%) participants had MAFLD and 35,359(74.58%) had MASLD. During the follow-up period, 849(1.7%) participants developed CKD. In participants with MAFLD, 345(2.7%) participants developed CKD, and in participants with MASLD, 609(1.7%) developed CKD. After adjustment for age and sex, the hazard ratio(HR) of CKD was 1.44 (95% confidence interval [CI] 1.25-1.66) for MAFLD, and 1.25(95% CI 1.07-1.47) for MASLD. Both definition predicted development of CKD nicely (Harrell’s C-index: 0.79(0.77-0.81) for MAFL and MASLD) Conclusions: The participants with MAFLD and MASLD showed significantly increased risk for CKD during a median of 15 years of follow-up. Both criteria showed nice predictability for CKD. Presentation: 6/1/2024