Background: Risk stratification systems may improve quality of care for patients with advanced lung cancer (ALC) by identifying those at high risk of rehospitalization and directing them to supportive care. The purpose of this study was to evaluate the implementation and preliminary efficacy of a risk-based system, with/without electronic patient-reported outcome (ePRO) symptom monitoring, to trigger supportive care for patients with hospital-diagnosed ALC. Methods: In this single-site, non-randomized, pragmatic study, patients in an academic center with hospital-diagnosed ALC were stratified to low or high risk using an established tool. High-risk patients were referred to two-pronged supportive care: patient navigation and outpatient palliative care. Eligible patients were recruited for 3 months of ePRO symptom monitoring coupled with provider alerts. Healthcare utilization was assessed at 90 days post-discharge. Program feasibility and acceptability were assessed using percent of eligible supportive care referrals made and completed, enrollment rates in ePROs, ePRO completion, and notifications to providers of concerning symptoms. Preliminary efficacy was defined as percentage of concerning ePRO symptoms resulting in new clinical action and 90-day readmissions. Results: At the time of interim analysis, 49 patients had been assessed with 48/49 (98%) identified as high risk. Patients had a mean age of 66 years, and were non-Hispanic, 51% male, and 22% Black. Patient navigation referral (92%) and completion (88%) was high. Palliative care referral (89%) and completion (45%) was lower. 14/39 (36%) of eligible patients enrolled in ePRO symptom monitoring, with competing priorities or feeling overwhelmed as the primary reasons for non-participation. Patient-level ePRO completion ranged from 0-100% (mean 53%). Nearly all (97%) concerning symptoms were reported to the clinical team; 27% of these resulted in new clinical action. By 90 days, 16/37 (43%) had hospital readmissions. Conclusions: Patient navigation was feasible and acceptable in patients with hospital-diagnosed ALC. However, there are ongoing barriers to implementation of post-hospitalization ePRO symptom monitoring and palliative care. Additional evaluation is needed to understand the barriers and facilitators and to measure the impact of navigation on patient outcomes. Since nearly all patients met high-risk criteria, future programs will eliminate risk stratification and target all patients with hospital-diagnosed ALC. Clinical trial information: NCT05722847.