Background: Due to disruptions in education, workforce entry, and career development caused by cancer and its treatment, young adult (YA) cancer survivors face financial toxicity (i.e., cancer-related financial distress) at rates higher than older survivors. Financial toxicity in YA survivors is associated with avoiding care and diminished psychosocial well-being, but enduring effects on employment, personal finances, and healthcare use and the association with YA’s financial capability are not well studied. Methods: This was a cross-sectional survey of a national sample of YAs with cancer (n = 214) recruited online and via mailing lists. It included the Comprehensive Score for Financial Toxicity (COST), demographic/clinical self-report, and questions on medical cost-coping and healthcare use. Financial capability questions considered respondents’ knowledge about finances, self-efficacy for managing health expenses, and attitudes and behaviors regarding tracking expenses, budgeting, saving, investing, and bill paying. Multiple linear regression assessed associations among financial toxicity, financial capability, and cost-coping. Results: Mean respondent age was 35.4 years (sd= 5.40) at survey and 27.5 years (sd= 7.23) at diagnosis. Breast cancer (28%) and lymphoma (17%) were the most common diagnoses; most respondents were white (79%) women (87%) with college degrees (74%). Financial toxicity, as measured by COST, was high (mean = 13.9, sd= 9.3; possible range 0-44, scores < 26 indicate severe financial toxicity). Nearly all of the sample (96%) had health insurance, but 30% said their insurance does not meet their needs. One-half of the sample lacked confidence to manage health expenses. Cost-coping strategies included skipping/delaying: treatment (23%), survivorship care (35%), or medications (39%); 65% relied on a family member to pay for some/all medical bills. Negative events related to medical expenses included using money from savings (58%), taking on credit card debt (45%), post-cancer credit score decrease (44%), borrowing money to pay bills (42%), debt collection contact (37%), lacking money to pay for basic necessities (23%), loan denial (20%), and thoughts about and/or filing for bankruptcy (15%). In multivariate analyses, greater financial toxicity was associated with lower self-efficacy for managing health expenses (β = -0.88, p =.01), poorer financial behaviors (β = -0.54, p =.001), lower income (β = -5.27, p =.001), and skipping/delaying: treatment (e^β= 1.16, p <.001), survivorship care (e^β= 1.13, p <.001), or prescribed medication (e^β= 1.10, p =.001). Conclusions: Our findings illustrate the profound enduring impact of financial toxicity among YAs after cancer treatment. Multilevel interventions are needed to provide YAs the tools to navigate financial aspects of the healthcare system and connect them with resources toward gaining financial independence.