Background: Targeted therapies based on oncogenic drivers demonstrate dramatic and durable response in patients with non-small cell lung cancer (NSCLC). However, acquired resistance inevitably develop by diverse genomic resistance mechanisms. Genotype-matched targeted therapies to overcome treatment-resistance have not been established, except osimertinib against EGFR T790M mutation. Methods: We established a nation-wide genomic screening project in treatment-resistant NSCLC (LC-SCRUM-TRY; UMIN000041957) in September 2020 to identify the genetic resistant alterations, and to promote clinical therapeutic development. Enrolled patients have been screened for genetic alterations using a rapid next-generation sequencing (NGS) system, Oncomine Precision Assay (OPA) for tissue samples, and Guardant 360 (G360) or OPA for plasma samples. MET amplification was also evaluated by FISH for NSCLC post EGFR-TKI treatment. Results: As of January 2023, 129 institutions in Japan were participating, and 1252 patients had been enrolled. Sample types were tissue (84%), and plasma (16%), respectively. Turn-around-time (median [interquartile range]) of OPA and G360 was 5 (4-6), and 9 (8-10.5) days, respectively. Of these, a total of 711 (57%) were already identified to have oncogenic driver at enrollment (EGFR, 556 [43%]; ALK, 70 [6%]; RET, 22 [2%]; ROS1, 21 [2%]; KRAS, 15 [1%]; ERBB2 exon 20 insertion [ex20ins], 8 [0.6%]; MET exon 14 skipping [ex14skip], 8 [0.6%]; BRAF V600E, 7 [0.6%]; NTRK3, 2 [0.2%]; others, 2 [0.2%]). Of 556 EGFR-mutated NSCLC, 537 (97%) were enrolled post EGFR-TKIs. EGFR mutation subtypes were exon 19 deletion (52%), L858R (41%), ex20ins (1%), others (6%), respectively. Of 537 EGFR-TKI resistant tumors, 326 (40%) had at least one genetic alteration related with drug resistance, including EGFR alterations (amplification [13%], C797S [4%], A750P [3%], E709X [2%], L792X [1%], L718Q [1%]), MET amp (16%), and other driver mutation/rearrangement (8%). Through this screening, 37 (7%) of patients resistant to EGFR-TKI were enrolled into clinical trials, with 16/102 (16%) patients with targetable alterations (MET amp or EGFR C797S). In addition, of 541 NSCLC without oncogenic drivers at enrollment, 116 (21%) were identified to have actionable oncogenic drivers with FDA-approved drug (KRAS G12C, 23 [4%]; ERBB2 ex20ins, 23 [4%]; RET, 13 [2%]; MET ex14skip, 13 [2%]; EGFR except ex20ins, [4%]; EGFR ex20ins, 10[2%]; ALK, 6 [1%]; ROS1, 5 [1%]). Conclusions: LC-SCRUM-TRY contributes to the clinical development of precision medicine to overcome drug resistance, especially for EGFR-mutated NSCLC resistant to EGFR-TKI. This screening platform also help to practice precision medicine for patients initially diagnosed as driver-negative. Clinical trial information: UMIN000041957.