The association between triglyceride-glucose (TyG) index and metabolic dysfunction-associated fatty liver disease (MAFLD) and its subtypes in the U.S. population remains unclear. This study aims to investigate this relationship.This study involved individuals aged 20 years or older who were not pregnant from the National Health and Nutrition Examination Survey (NHANES) between the years 2017 and 2020. MAFLD diagnosis was established by identifying the occurrence of liver steatosis through ultrasound transient elastography, along with the presence of one or more of the following disorders: diabetes mellitus (DM), overweight or obesity, or metabolic disorders. We evaluated the association between TyG index and MAFLD using multivariable regression analysis.Our study included 2966 participants with a mean age of 46.9 ± 16.5 years. As TyG quartiles increased, MAFLD incidence increased (P < 0.001). Full model adjustment indicated that TyG was independently connected with MAFLD (OR = 2.53; 95% CI = 2.13-3.00]), with the maximum quartile exhibiting the highest risk. In men, the TyG index and MAFLD exhibit a nonlinear J-shaped relationship (P = 0.042), whereas in women, the relationship was linear and positive (P = 0.204). This association was found to be more pronounced in Mexican Americans, those who were not overweight or obese, and among individuals without chronic kidney disease (CKD) (all P for interaction < 0.05).The TyG index was an independent risk factor for MAFLD. Individuals with various MAFLD components require individualized management.© 2025. The Author(s).