Abstract Background/Aims: Racial health disparities have been linked to racial and residential segregation. Redlining bias is a special form of racial and residential segregation involving the systematic denial of mortgages, insurance, and other financial services to racial/ethnic minorities. This study examined associations between redlining bias and the progression of chronic health conditions (CHCs) in adult survivors of childhood cancer. Methods: We included 1,670 adult survivors of childhood cancer from the St. Jude Lifetime Cohort Study who had undergone two or more clinical assessments. Over 200 individual CHCs were graded using a modified CTCAE version and aggregated to determine the global CHC burden. CHC progression from baseline to follow-up evaluation was classified as either worsening over time (from Grade 2 to 3-5 or from Grade 3 to 4-5) or new-onset (from Grades 0-1 to 2-5). Survivors' home addresses at baseline (2007-2020) were linked to contemporary redlining bias data (2010-2017) created by Beyer et al. (J Clin Oncol, 2021). Redlining bias was defined as the odds ratio of a mortgage application denial for properties in a local area versus all metropolitan statistical areas and further classified as high (≥2.0), moderate (1.0-1.9), low (0.5-0.9), or least bias (<0.5). Multivariable logistic regression tested associations of risk for worsening/new-onset CHCs (vs. no progression) with redlining bias (high vs. moderate/low/least bias), adjusting for age, sex, treatment factors, personal socioeconomic status (SES; education and health insurance), and lifestyle factors. Joint effects of redlining bias and personal SES on CHC progression were also evaluated. Results: Survivors’ mean±SD age at baseline was 31.7±8.3 years; 17.5% lived in high and 19.5% in moderate redlining neighborhoods. The bivariate analysis found that living in a neighborhood classified as having high redlining bias (vs. moderate/low/least bias) increased the risk of progression of the global burden of CHCs (OR=1.32, 95% CI: 1.02-1.70). Multivariable analysis found significant associations of redlining bias with the risk of worsening/new-onset of individual CHCs such as cardiomyopathy (OR=1.63, 95% CI: 1.07-2.48), peripheral motor neuropathy (OR=1.56, 95% CI: 1.00-2.44), asthma (OR=1.85, 95% CI: 1.04-3.32), and restrictive pulmonary deficit (OR=1.79, 95% CI: 1.05-3.04). Considering joint effects, survivors enrolled in public insurance programs and living in a high redlining area had a higher risk of progression of the global burden of CHCs (OR=1.73, 95% CI: 1.05-2.87) and of worsening/new-onset in peripheral motor neuropathy (OR=3.18, 95% CI: 1.57-6.42) and restrictive pulmonary deficit (OR=5.29, 95% CI: 2.46-11.37) CHCs. Conclusions: The significant associations of redlining bias with the progression of CHCs among adult survivors of childhood cancer suggest an urgent need for interventions (typically social or healthcare policies) targeting neighborhoods with high discriminatory exposures to prevent CHC burden in this population. Citation Format: Jaesung Choi, Madeline R. Horan, Nickhill Bhakta, Deo Kumar Srivastava, Kirsten K. Ness, Gregory T. Armstrong, Melissa M. Hudson, I-Chan Huang. Redlining bias and progression of chronic health conditions in survivors of childhood cancer: A report from the St. Jude lifetime cohort study [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr B139.