Introduction: Neurotrophic tyrosine receptor kinase (NTRK) gene fusions are present across various tumor types with an estimated overall prevalence of <1%. Tropomyosin receptor kinase inhibitors (TRKis) block the constitutively activated tyrosine receptor kinase (TRK) fusion protein produced in NTRK gene fusion positive (NTRK+) patients from downstream signaling. Many treatment guidelines now include TRKis as first- line(1L) or subsequent treatment options for TRK fusion cancer. This study aimed to assess timing of NTRK gene fusion testing and treatment modifications following NTRK+ status. Methods: U.S. medical oncologists from the Oncology Provider Extended Network who had treated NTRK+ advanced/metastatic(adv/met) solid tumors completed a questionnaire in September 2020. The questionnaire collected physicians’ use of NTRK testing in routine clinical practice among patients(pts) with adv/met solid tumors. Responses were summarized using descriptive statistics. Results: A total of 28 medical oncologists throughout the U.S. (South , Northeast , West , Midwest ) completed the study questionnaire. Participating physicians represented private community practices (71%), hospital/academic affiliated practices (25%), and solo practice (4%), having managed or treated 148 NTRK+ adult pts diagnosed with adv/met solid tumors between 01/01/2016-12/31/2019. Tumor types most commonly tested were lung (27%), thyroid (18%), and salivary gland (14%). Two-thirds (68%) of physicians’ test NTRK status at diagnosis (i.e., prior to 1L initiation); testing following disease progression on 1L (36%), 2L (25%), and 3L (21%) was also common (Fig). Most physicians (96%) reported no difficulty interpreting NTRK reports. Nearly all physicians (96%) indicated using next-generation sequencing (NGS) for determining NTRK status. Majority of physicians (57%) indicated that age, tumor type, and performance status did not impact NTRK testing decisions. Less than half (46%) of physicians include TRKis following NTRK+ determination. NTRK testing guidelines were commonly reviewed by physicians (89%). Conclusion: Among NTRK+ pts, medical oncologists reported testing for NTRK fusions at diagnosis or prior to 1L. Future research should elucidate why less than half of oncologists surveyed would not use TRKis after TRK+ confirmation and assess actual clinical practices among NTRK+ pts, as well as characterize treatment patterns and clinical outcomes among NTRK+ pts in the real-world setting.