284 Background: Biomarker testing is critical for optimal therapy selection in non small cell lung cancer, but it takes time and may delay treatment, causing patient anxiety and dissatisfaction. Patients want to understand the necessity and timing of biomarker testing and therapy decisions, but clinicians find these discussions challenging, especially with lower health literacy patients. As a solution, we deployed 4R Oncology model (4R = Right Info/Care/Patient/Time) at 10 centers (4 safety net, 6 non safety net). Under 4R, clinicians discuss with patients a Care Sequence, a predeveloped care checklist with visual timing of care, emphasizing biomarker testing within the overall care plan. It includes social and supportive care to address Social Determinants of Health (SDOH). Methods: Interviews with clinicians to examine whether / how Care Sequence helped discuss the need and timing for biomarker testing with patients, including lower health literacy patients. The cohort of clinicians (N=18) included oncologists, fellows and nurses; 10 worked at safety net centers. Results: All clinicians reported that Care Sequence helped explain timing of biomarker testing and the need to wait for results (Table). The majority reported that it helped discussions with lower literacy patients and to train fellows how to discuss these issues and place related referrals. These benefits and most of the rationale were reported at a similar rate by safety net and non safety net clinicians. Conclusions: The 4R Care Sequence is a promising quality tool that helps clinicians, including fellows, manage patients’ awareness and expectations for timing of biomarker testing and therapy decisions in lung cancer. The benefits in discussions with lower health literacy patients at both safety net and non safety net centers suggest that 4R can address disparities in patients’ understanding of these complex issues and may reduce anxiety while awaiting treatment. Does Care Sequence help / rationale % of all clinicians N=18 % of safety net clinicians n=10 % of non safety net clinicians n=8 P value Helps Explain Timing of Biomarkers & Decision, Need to Wait for Results 100 100 100 1 - Describes how biomarker testing fits into overall care plan 94 100 88 .4 - Visually depicts timing of testing & treatment decision 83 80 88 1 - Recommends patients to be active preparing for treatment while waiting 78 80 75 1 - As a standard, normalizes timing of results, decisions 56 30 88 .02* Helps Discuss With Lower Health Literacy Patients 89 90 88 1 - Combines visual timeline & succinct checklist 61 60 63 1 - Uses plain language as possible 39 60 13 .02* - Helps address SDOH while waiting 72 70 75 1 Helps Train Fellows 92 100 67 .2 - Reminds to order biomarkers, other workup 77 80 67 1 - Helps develop narrative, organize discussion of biomarkers 77 80 67 1 - Prompts to discuss SDOH, refer to related care 62 80 0 .04* *Statistically significant, p<.05.