Background: We previously showed the significant extent to which legal barriers requiring appropriate navigation are encountered by patients with cancer and their caregivers. Despite this, structured training on legal topics is not offered for healthcare workers (HCW). We performed a nationwide analysis to ascertain baseline legal knowledge in HCWs, and investigate the impact of a training program aimed at improving knowledge gaps in legal, financial, and social services navigation. Methods: This is a retrospective analysis of HCWs participating in legal and financial training sessions from 2021-2023 led by attorneys from Triage Cancer, a nonprofit organization providing free education on legal issues that impact individuals with cancer. Pre-training surveys assessed baseline knowledge, comfort, and frequency with which HCWs counseled patients with cancer, on legal barriers. Impact of training was evaluated via surveys at 1 week and 6 months post-training. Survey scores were descriptively analyzed to summarize changes in knowledge compared to baseline. Paired t-tests evaluated self-rated competence before and after legal training. Results: The pre-intervention survey was completed by 2141 HCWs who were primarily White (63.9%), female (89.8%), and social workers (39.3%) during the most recent survey year. HCWs served patients of ≥20 cancer types including breast (33.4%), hematologic (12.7%), and lung (6.9%), and reported assisting patients with health insurance options (82.6%), financial navigation (53.3%), and disability insurance claims (46.5%). Only few HCWs reported feeling “comfortable” or “very comfortable” assisting patients with health insurance (22.1%), finances (17.2%), or disability insurance (9.5%). The 1-week and 6-month post-intervention surveys were completed by 852 and 211 individuals, respectively, and standardized questionnaire scores demonstrated improvement in tested knowledge from baseline (26% questions correct) to 1-week (67.5%) and 6-month (35%) follow-up. Self-rated improvement in HCW competence following intervention at 1-week (surveyed using 10-point scale, mean improvement 3.14, 95% CI [3.05, 3.25]) and 6-months (corrected mean improvement 2.52 [2.29, 2.75]) were significant (p < 0.001 for both). At 6-month follow-up, 90.5% of surveyed HCWs reported changing behavior or practice based on the training, noting the education facilitated patient care through navigation of health and disability insurance and appeals; reducing financial burden, stress, and anxiety; and improving quality of life (Likert scales ranged 3.17-3.41 with 3 for Agree and 4 for Strongly Agree). Conclusions: This study showcases the necessity, success, and practicality of implementing a legal training for HCWs who note high frequency of legal concerns from their patients, but lack the comfort or expertise in appropriately navigating these.