PURPOSE: Financial toxicity is an adverse outcome of cancer care and is often quantified by patient-reported validated survey tools, such as The Comprehensive Score for Financial Toxicity (COST). We aimed to examine the association of objective financial measures of hospital out-of-pocket (OOP) expenses and write-offs with the patient derived COST scores in patients with gynecologic cancer. METHODS: We identified individuals who completed our cross-sectional survey in discrete periods between 2017 and 2021. Response rates for these periods ranged from 75 to 95%. Hospital financial data was abstracted for respondents, including OOP payments and write-offs in the year before survey completion. Write-offs occurred when patients did not complete payments and included bills forgiven by the hospital or sent to collections. Chi-square, Fisher's exact, Kruskal-Wallis, and Cochran-Armitage tests were used to compare variables. RESULTS: Among 323 respondents, median COST score was 29 (IQR 22-36) and 13% had severe, 25% moderate and 62% mild financial toxicity. Increased financial toxicity was associated with age, race, partner, employment status, insurance type, and income (p <
0.05). Most (63%) respondents had OOP payments and 31% had write-offs. The moderate financial toxicity group had the highest median OOP payment (99 (46-,004)) as compared to those with severe and mild financial toxicity (p = 0.01). Meanwhile, those with severe financial toxicity were more likely to have a write-off (44%), compared to the moderate and mild financial toxicity groups (p trend = 0.02) and had the highest median write-off amount (17 (50-27), p = 0.03). CONCLUSION: Patient-reported financial toxicity is associated with objective financial measures of hospital out-of-pocket costs and write-offs.