Abstract Introduction: Type 2 diabetes (T2D) is associated with over 2 times increased risk of hepatocellular carcinoma (HCC). Low-income status is associated with a higher risk of developing HCC, more advanced stage, and mortality. Evidence is limited on whether income dynamics are associated with the risk of developing HCC in individuals with T2D who are susceptible to income changes. We examined whether income levels and income changes are associated with HCC risk. Methods: Using representative data from the Korean National Health Insurance Service (NHIS), 2,227,893 adults with T2D (aged ≥ 20 years) without a cancer history were included between 2015-2016. Income levels were measured based on health insurance premiums and categorized into 4 levels (quartiles [Q], 1 [low income], to 4 [high income]). These quartiles excluded the very low-income individuals who qualified as Medical Aids beneficiaries (MAB), which comprised a 5th income category. To identify income change, income levels were collected annually from the baseline year backward 4 years. The incident HCC, defined based on ICD-10 codes and special reimbursement codes, was identified until December 2020. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated to assess the association between income parameters and HCC after adjusting for sociodemographic factors, comorbidities, and diabetes duration and treatment. Income parameters included 1) the baseline income status, 2) the cumulative number of years being in each income level, and 3) changes in income level between the two time points (4 years ago vs. baseline). Results: During follow-up (median, 3.9 years), 9,887 HCC cases developed. Individuals who had experienced at least one episode of MAB during the five years showed a significantly higher HCC risk than those who had never qualified as MAB (HRs ranging from 1.52 to 2.01). In contrast, individuals who had experienced high-income status (Q4) during the five years had a lower HCC risk than those who had never experienced (HRs ranging from 0.79 to 0.92; HRn=5 years vs. n=0 years 0.79, 95% CI 0.75-0.83; P for trend <0.05). Individuals in the low-income status (MAB-Q1) at the first assessment (4 years ago) but experienced increased income had a reduced risk of HCC, which linearly declined with increasing income rise. Also, those who experienced a substantial increase in income up to the top quartile (Q4) had the lowest HCC risk (HR 0.73, 95% CI 0.60-0.88; P for trend<0.05) than those who maintained the low-income status. Conclusions: Experiencing any very low- or high-income state was independently associated with increased or decreased HCC risk. Improved income levels among those in the low-income status had an inverse linear association with reduced HCC risk. Our findings underline the need for increased public policy awareness of the impact of income dynamics on HCC risk in adults with T2D. Citation Format: Jongha Baek, Benjamin C. Amick III, Clare C. Brown, Mario Schootman, Marie-Rachelle Narcisse, Seung-Hyun Ko, Pearl A. McElfish, Michael R. Thomsen, Seong-Su Lee, Kyungdo Han, Yong-Moon Mark Park. Income dynamics and the risk of hepatocellular carcinoma in individuals with type 2 diabetes: A nationwide population-based cohort study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4865.