305 Background: Adolescents and young adults with cancer experience high rates of financial toxicity (FT) and unmet health-related social needs (HRSN: food, housing, transportation insecurity). FT and unmet HRSN, specifically FI, are modifiable factors that impact health outcomes; however, the relationship between FI, FT, and healthcare utilization (emergency department (ED) visits or hospitalizations) remains unclear. Leveraging systematic screening for FT and HRSN using the electronic health record (EHR) patient portal among AYAs with cancer, we examined the association between FI, FT, and healthcare utilization measures among AYAs with cancer. Methods: AYAs (ages 15-39) who utilize the EHR patient portal were prompted to complete an 8-item standardized HRSN survey (i.e., food insecurity, housing instability, transportation difficulties) and a 2-item previously established FT survey during e-check in between November 2022 and April 2024. ED visits and hospitalizations were extracted from the EHR directly. Descriptive statistics and associations using chi-square tests were used to describe the patients and examine associations between FI or FT and ED visits or hospitalizations. Results: Of 691 AYAs who completed the HRSN survey, 16% (n=109) screened positive for FI. Among AYAs with FI, 42% (n=46) had at least one ED visit compared with 28% (n=163) among AYAs without FI (p<0.01). Among AYAs with FI, 39% (n=43) were hospitalized at least once compared to 31% (n=179) among AYAs without FI (p=0.07). Of 439 AYAs who responded to the FT survey, 66% (n=290) met criteria for high FT. Within this group, 26% (n=74) had at least one ED visit compared with 17% (n=26) who screened negative (p=0.06). Among AYAs with high FT, 22% (n=65) were hospitalized at least once, compared with 19% (n=28) among those with low or moderate FT (p=0.38). Among 384 AYAs who responded to both the HRSN and FT surveys, 19% (n=74) screened positive for FI, 92% (n=68) of whom also had high financial toxicity. The table describes characteristics of screened AYAs by language and race/ethnicity. Conclusions: FI may be a risk factor for increased ED visits during cancer treatment among AYAs. Systematic screening to identify FI, FT, and other HRSN is important to facilitate referral for resources, support services, or interventions. Sociodemographic characteristics of AYA participants in FI and FT screening. Characteristic +FI -FI +FT -FT N=109 (%) N=582 (5) p-value N=290 (%) N=149 (%) p-value Language <0.01 <0.01 English 82 (75) 496 (85) 241 (83) 134 (90) Spanish 24 (22) 45 (8) 29 (10) 1(1) Other 3 (3) 41 (7) 20 (7) 14 (9) Race/Ethnicity <0.01 <0.01 Hispanic, any race 67 (61) 175 (30) 125 (43) 16 (11) Non-Hispanic Black 12 (11) 62 (11) 30 (10) 10 (7) Non-Hispanic White 16 (15) 219 (38) 78 (27) 84 (56) Other 14 (13) 126 (22) 57 (20) 39 (26)