Background: The number of targeted therapies approved for treatment of mNSCLC has increased over the past 5 years. Strategies to identify eligible patients with actionable mutations for targeted therapy include simultaneous testing of ≥ 2 genes via next generation sequencing (NGS) or multiple simultaneous gene testing (MSGT) and sequential single gene testing (SSGT). Current clinical practice guidelines strongly recommend broad molecular profiling in all patients for the simultaneous assessment of multiple genes, including EGFR, ALK and ROS1, that may have potential roles in cancer development. Limited real-world (RW) evidence is available describing the uptake of these strategies and receipt of targeted therapy. Methods: Medicare beneficiaries age 65 years or older, newly diagnosed with mNSCLC and tested for mutations of interest in mNSCLC (ALK, EGFR, ROS1, BRAF, HER2, KRAS, MET, NTRK, RET) from July 2014 - June 2018 were identified using Medicare FFS claims (100% sample) linked to biomarker results in PROGNOS NSCLC Explorer. Patients were followed from date of first metastatic diagnosis and stratified by line of therapy, testing strategy, and year of mNSCLC diagnosis. Those testing positive for an actionable biomarker were identified and then segmented by timing of receipt of a subsequent targeted therapy. Results: 12,272 beneficiaries met inclusion criteria: median age: 75 years, 51% were female, 86% white. Among mNSCLC patients with at least one biomarker test result, EGFR and ALK mutation status were the most commonly tested and reported in 85% and 63% respectively. Overall, 1540 (12.5%) tested positive for EGFR, ALK or ROS1. The relative use of NGS or MSGT vs. SSGT for biomarker testing increased over time, from 63% in 2014 to 80% in 2018. During this period, 789 patients were identified as having at least one positive biomarker test result prior to initiating 1L therapy: 635 were identified via NGS or MSGT while 154 were identified via SSGT. Despite a positive test for mutations of interest, only 292 patients received a targeted drug at 1L. Conclusions: This RW study of mNSCLC patients demonstrates an increasing trend to test patients for multiple biomarkers at once via NGS or other MSGT methods. The number of patients receiving appropriate targeted therapies was low, suggesting the need to address the barriers to administration of guideline-recommended therapy.