Immune checkpoint inhibitors (ICIs) represent a significant benefit for the initial treatment of patients with advanced or metastatic non-small cell lung cancer (NSCLC). Beyond clinical benefit of increased overall survival, it represents a class of medications with a favorable adverse effect profile compared with chemotherapy. Drugs that target programmed cell death protein 1 (PD-1) receptor and its ligand PD-L1 are ICIs that work by taking the brakes off the immune system and promote T-cell-mediated cancer cell destruction. Current NCCN guidelines recommend that all patients with advanced or metastatic NSCLC have their PD-L1 status (amount of PD-L1 on cancer cells) assessed to guide treatment section. However, this recommendation is not always followed and may lead to inappropriate treatment selection and potential increased cost. Through appropriate biomarker testing, subsequent appropriate utilization of ICIs may help to drive down other costs and improve health-related quality of life. Managed care pharmacists should continue to focus on promotion of guideline concordant care that includes appropriate biomarker testing and selection of an evidence-based preferred treatment option.