Human induced pluripotent stem cell (hiPSC)-derived hepatic models, including 2D hepatocyte-like cells (2D HLCs) and hepatic organoids (HOs), are valuable in vitro models for evaluating the safety and efficacy of drugs. However, 2D HLCs show limited expression and activity of drug-metabolizing enzymes, particularly cytochrome P450 (CYP450), which are involved in detoxification, a major liver function. HOs have more mature properties than 2D HLCs, particularly enhanced CYP450 gene expression. However, the transcriptional regulatory mechanisms that correlate with CYP450 expression in HOs remain unclear. Here, we identified epigenetic states around transcriptional regulatory regions and compared them with those in primary human hepatocytes. We found that significantly higher CYP450 gene expression in HOs than in 2D HLCs was strongly associated with DNA methylation and histone acetylation in their regulatory regions. Therefore, these results suggest that mature epigenetic regulation may have an impact on drug metabolism and toxicity outcomes in hPSC-derived hepatic models and, hence, be used as an indicator of model maturation. Funding source: This research was supported by the Korea Institute of Toxicology (Grant No. 2710086911) and the National Research Foundation of Korea (NRF) grant funded by the Korea government (MIST, Grant No. RS-2023-00210505).