Background: Lung cancer (LC) is the leading cause of cancer-related deaths worldwide. Tobacco smoking is implicated as the causative factor in 85% of LC. The U.S. Preventive Services Task Force (USPSTF) and National Comprehensive Cancer Network (NCCN) recommendations for annual low-dose CT chest (LDCT) for LC screening in high risk adults who meet appropriate criteria, which primarily focuses on age and smoking history. Medicare coverage for LC screening for eligible individuals went into effect in February 2015. Despite this, screening rates remain low and patients with LC are typically diagnosed at a later stage. We conducted a single center retrospective analysis of patients with established diagnosis of lung cancer to evaluate if screening guidelines were appropriately followed prior to the cancer diagnosis. Methods: Patients diagnosed with LC between 2016 and 2019 were included in the analysis. Charts were reviewed for demographics, detailed smoking history, as well as histology and stage of LC. Associations between categorical factors and screening and were examined using the chi-square test. Associations between continuous and ordinal factors and screening and were examined using the Mann-Whitney test. Results: A total of 530 charts were reviewed. Of those, 52.5% (278) met NCCN and/or USPSTF criteria and 10.8% (30/278) underwent screening. The median age for those who were screened was 69 years. There was no association between age at diagnosis and screening. There was a significant association between active smoking status and screening (p < 0.0191). An average of 16.8% (16/95) of current smokers and 7.7% (14/183) of former smokers were screened. Patients who had screening CT scans were diagnosed at earlier stages of LC compared to those who were not screened (p < 0.0083) [table]. Conclusions: Our study showed that despite established guidelines for LC screening and insurance coverage, a vast majority of screening-eligible LC patients have never had LDCT. We found that patients who underwent screening as per guidelines were diagnosed at earlier stages of disease compared to those not screened, which goes along with published data. Ongoing efforts to increase awareness and adherence to LC screening guidelines will be of paramount importance in improving early detection and reducing mortality from LC.